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The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study
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Original Article
The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study Aly Okasha a,∗ , A.M. Abdelghany a,b , S.Y. Marzouk c a b c
Spectroscopy Department, Physics Division, National Research Center, 33 ElBehouth St., Dokki, 12311, Giza, Egypt Basic Science Department, Horus University, International Coastal Rd, New Damietta, Kafr Saad, Damietta, Egypt Basic and Applied Science, Faculty of Engineering, Arab Academy of Science and Technology, Al-Horria, Heliopolis, Cairo, Egypt
a r t i c l e
i n f o
a b s t r a c t
Article history:
Two glasses compositions (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy)
Received 13 September 2019
where x = 0.0.5%, and 1.0% in wt.% ratio were prepared using melt quenching technique
Accepted 12 October 2019
in order to investigate the effect of Ba2+ and Sr2+ ions in Dy3+ ions doped lead borate glass.
Available online xxx
The optical properties such as bandgap and the refractive index distribution were examined using UV–vis-NIR absorption spectroscopy. The FTIR absorption spectra of all prepared
Keywords:
samples were similar except for the metallic bands in the fingerprint region. The obtained
Lead borate glasses
experimental data were compared with theoretical data calculated by Judd–Ofelt framework.
Optical properties
The Judd–Ofelt parameters ( = 2, 4 and 6) were calculated and the trend was 2 < 4 < 6
Judd–Ofelt theory
which is the common trend. The experimental oscillator strength (fexp ), the calculated oscillator strength (fcal ), the estimated refractive indexes (n) at each transition, the lifetime of radiative transitions (), the branching ratio (ˇ), the absorption cross-section ( abs ()) and the emission cross-section ( emis ()) were also estimated and discussed. The optical gain coefficient (G()) was calculated not only for the most intense emission transition but also other emission peaks. The obtained results indicated that the prepared samples are promising materials for laser emission and optical communication applications. © 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1.
∗
Introduction
During the last two decades, the using of the glasses material attracts enormous attention. Among the glasses material the borate glass containing transition metals, such as ZnO, PbO, TeO2 Bi2 O3 , MgO, CaO, SrO, and BaO, attracts great attention
Corresponding author. E-mail: [email protected] (A. Okasha). https://doi.org/10.1016/j.jmrt.2019.10.029 2238-7854/© 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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due to the ability to tailoring its properties to fit special applications. Recent developments in the field of borate glasses have led to a renewed interest in the fields of leasing and Opto-communications materials, optical filters and photonic devices [1]. Several attempts have been made to investigate the modified lead borate glasses materials. In that manner, Shaw et al. [2] and Zuh et al. [3] studied the phase separation of the lead borate glasses. Besides, Xi et al. [4] and Wang et al. [5], were reported that the ratio of PbO/B2 O3 is playing an essential role in the structure of the glass network. Adding heavy metal oxides, such as BaO and SrO, to the lead borate glasses is one of the most widely used methods to tailoring the optical properties and radiation shielding of the glasses [6]. The great change in the optical properties of the glasses was experienced by adding a rare earth element to the structure of the glasses. Pisarska et al. [7] studied the lead borate glass contains Dy3+ ions and investigates the luminance properties in the presence of Al2 O3 and WoO3 . In their study, the absorption and luminance properties of the glass were investigated and compared by the estimated theoretical values using Judd–Ofelt (J–O) calculation. The same group studied the Dy3+ luminance transitions 6 H11/2 at 662 nm, 6 H113/2 at 573 nm and 6H 15/2 at 480 nm [8]. In addition, the yellow/blue luminescence of trivalent Dy was studied as a function of the B2 O3 /PbO ratios in the presence of Cr3+ as an alkaline metal [9]. So far, however, The research to date has tended to focus on investigation the luminance properties of lead borate glasses containing Dy3+ in the visible spectral region rather than the IR spectral region [7–9]. In the present study two glass series were prepared, (50B2 O3 –30PbO–20BaO–XDy), and (50B2 O3 –30PbO–20SrO–xDy) where x = 0, 0.5% and 1%. The study has tended to focus on studying the optical properties of the lead borate glass containing Dy3+ ions in the presence of two alkali earth metal oxides (BaO and SrO) in both the visible and the IR region. The experimental data will compare with the theoretical data obtained from the J–O framework to estimate the absorption and luminance characteristics to investigate the suitability of the studied glasses in the optical communication fiber.
2.
Experimental details
2.1.
Samples preparation
Two glass systems of nominal composition (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy) where x = 0.0.5%, and 1.0% in wt.% ratio, were prepared using pure chemical reagents including orthoboric Boric acid, H3 BO3 (Laboratory Rasayan Sd Fine-Chem. Limited), lead Oxide, PbO (Sisco research Lab. India), Barium Oxide BaO, and Strontium Oxide, SrO from (Panreac Quimica SA, Espana), Dy3 O2 (99.99%, Aldrich Chemical Co) which were used as received without any farther purifications. The melt quenching technique was used in glass synthesis under atmospheric conditions. In the typical method, weighted materials were mixed carefully and melted at 1100 ◦ C using an electric furnace for about 2 h in platinum crucibles. In the next step, samples were cast in a stainless steel mold and transferred into a muffle furnace and kept at 400◦ C for annealing for 2 h, then the furnace was left
Fig. 1 – UV–vis-NIR absorption spectra.
to cool down to the room temperature overnight. Six samples were cut, polished and smoothed in 1 cm × 2 cm (±0.1 mm) rectangular shape with 2 mm (±0.1 mm) thickness. Finally, the samples named (base Ba), (0.5 Dy Ba), (1.0 Dy Ba), (Base Sr), (0.5 Dy Sr) and (1.0 Dy Sr) as shown in Table 1.
2.2.
Glass density measurements
The traditional Archimedes method was used to determine the glass densities at room temperature by weighing the samples in both air (wtair ) and weighed in submerged xylene (wtimmeresed ). The density of the glass (D) is estimated from the equation: D
g cm3
=
wtair × 0.863 wtair − wtxylene
(1)
where, 0.863 represents the xylene density in units of g/cm3 . All measurements were performed in triplicate different samples for error elimination and estimation. The results of the density measurements were illustrated in Table 1.
2.3.
Optical absorption and infrared measurements
The absorption spectra of the samples under investigation were carried out using (JASCO model V730 Japan) spectrophotometer and the results were illustrate in Fig. 1. While, the FTIR spectra of the samples measured using (Bruker Model Vertex 70) Spectrometer using the KBr disc technique in the spectral range 4000–400 cm−1 . The FTIR spectra were demonstrated in Fig. 4.
3.
Results and discussion
3.1.
Optical absorption
The absorption spectra in the UV–vis-IR spectral range from 300 nm to 2000 nm were illustrated in Fig. 1 the inset shows the sample (1.0 Dy Sr) focused on the range from 425 nm to 550 nm headed for identifying the two absorption peaks at
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Table 1 – Glass symbols, direct and indirect optical band gap, Eg; glass density, D; and the refractive index n. Sample symbol
Density, D (g/cm3 ) ±0.018
Direct optical band gap, ± 0.05 (eV)
Indirect optical band gap,± 0.05 (eV)
n
Base Ba 0.5 Dy Ba 1.0 Dy Ba Base Sr 0.5 Dy Sr 1.0 Dy Sr
4.87 4.80 4.76 4.78 4.73 4.63
2.91 2.91 2.91 2.91 3.00 3.79
3.42 3.41 3.43 3.51 3.53 3.41
1.43 1.43 1.43 1.43 1.42 1.37
Fig. 2 – (a) Direct band gap for allowed transitions, (b) indirect band gab for allowed transitions.
Fig. 3 – (a) Reflectance distribution and (b) represent the refractive index distribution.
448 nm and 476 nm which corresponding to the transitions 4I 4 15/2 , F15/2 respectively. In addition, the mean figure showed other means six peaks at 748 nm, 798 nm, 900 nm, 1090 nm, 1267 nm and 1672 nm which are corresponding to the transitions, 6 F3/2 , 6 F5/2 , 6 F7/2 , 6 F9/2 , 6 F11/2 , and 6 H11/2 respectively. The intensities of all transitions increase by increasing both Ba3+ and Sr3+ in the samples. The same results were reported by Marimuthu et al. [10]. They observed that the transitions 4 I15/2 , 4F 3+ ions are relativity weak comparing with the 15/2 of the Dy other transitions due to the strong host lattice absorption in the UV region.
3.2.
Calculations of the optical band gap
The fundamental optical band gap (Eopt ) of the two studied glasses systems has no sharp edges as shown in Fig. 1. However, by using Beer–Lambert–Bouguer law, with simple
modification the optical band gap energy calculated thought the equation [11]: m
(∝ hω) = C (hω − Eopt )
(2)
where m take values of ½ or 2 for direct allowed, indirect allowed transitions respectively, C is a constant and ˛ is the absorption coefficient. The optical band gap values were obtained by extrapolating the linear region of the plot of Eq. (2) for m= ½ was illustrated in Fig. 2-a, while the fitted one for m = 2 was illustrated in Fig. 2-b. It is observed that the value of the optical band gap in case of direct allowed or indirect allowed transitions for the Ba system glass nearly does not change with increase the Ba, and the value is around 2.97 and 3.41 eV respectively. On the other hand, for Sr system, the direct-allowed decrease from 3.11 to 2.88 eV, and indirect allowed transitions band gaps decreases from 3.50 to 3.41 by
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Table 2 – FTIR band position and assignments. IR peak position (cm−1 )
Peak assignment
∼460 ∼617 ∼694 ∼944 ∼1214
Vibrations of metal cations Ba2+ or Sr2+ Binding O—B—O Combination vibration of BO4 and PbO4 groups B—O—B linkage Asymmetric stretching of B—O bonds from orthoborate groups Presence of pyriborate, orthoborate groups containing BO3 Hydrogen bonding OH group
∼1340 ∼2923 ∼3430
3.4.
Fig. 4 – FTIR absorption spectra for all glass samples.
increasing the Sr content. However, directly allowed or indirect allowed band gap increase by increasing the Dy3+ in the samples. These results are in agreement with Marimuthu et al. [10] findings. The optical band gap energies have been used to determine the different values of refractive index (n) by using Dimitrov and Sakka relation [12].
− 1) =1− (n2 + 2) (n2
from an initial state, (S, L) J, to final excited state, S , L J , is depending on the Judd–Ofelt parameters ( = 2,4,6) and is given by:
fcal (S, L) J; S’ , L’ J’ =
˝ (S, L)J
82 mc (n2 + 2) × 9n 3h(2J + 1)
’ ’ ’ 2
U S , L J
2
(4)
=2, 4, 6
(3)
where Eg is the direct optical band gap for allowed transitions. The refractive index values enlisted in Table 1. The reflectance distribution and the refractive index distribution are shown in Fig. 3-a and -b). The two figures indicate the sensitivity of the reflectance distribution and the refractive index distribution to the different transitions of Dy3+ .
3.3.
The calculations of the radioactive transitions properties illustrated by Judd–Ofelt theory [14,15] is important to understand the optical properties of the Dy3+ doped glasses in both the two matrix which contain Ba or Sr. The calculation in this work suggest that the calculated oscillator strength of an electronic dipole absorption transition, fcal (S, L) J; S , L J ,
× Eg 20
Judd–Ofelt calculations
FTIR absorption spectral data
FTIR absorption spectra are demonstrated in Fig. 4. The network observed in the studied two glasses systems are in the main three infrared bands. The band around ∼794 cm−1 which related to the combination of both phosphate and borate groups (BO3 and BO4 ) with the first phosphate partner. The band <750–1150 cm−1 related vibrations of both non-bridging PO2 groups and the stretching vibrations of BO3 groups. The band <1150–1600 cm−1 related to (OH), POH, and BOH vibrations. In addition to the vibrations of metallic cations at about 460 cm−1 . The peak at about 2920 related to the hydrogen bonding, while the peak at about 3400 related to the OH group. There was no change in the absorption band between the studied samples. The previous study has reported the same results using NF3 phosphate glasses [13]. The detailed band assignment are showed in the Table 2.
where m is the electron mass, h is the Plank’s constant, is the wavelength, n is the refractive index of the glass,
and U is the doubly reduced matrix of the unit tensor obtained from Weber [16] were applied respectively. By applying the samples parameters (e, l, N, and OD()) the experimental oscillator strength of an electronic dipole absorption transition fexp is given by:
fexp
mc2 = 2.303 lNe2
OD () d d2
(5)
where e is the electron charge, N is the number of active ions per unit volume, l is the sample thickness, and OD() is the optical density. The Judd–Ofelt parameters ( = 2,4,6) calculated using the least squares fitting method (r.m.s.) according to the selection role |S| = 0, |L|≤ 2, |J|≤ 2 [17]. The fitting accuracy between the calculated and the experimental parameters was estimated using the equation:
r.m.s. =
(f
− fmeas )2 P−3
calc
P
12 (6)
where P is the number of observed transitions on the absorption spectrum. However, the values of r.m.s. is small and the values of fcal and fexp , is closed to each other. The results of the fcal , fexp , ˝ and r.m.s. are illustrated in Table 3.
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Table 3 – Calculated (fcal ) and (fexp ) experimental oscillator strengths along (from the ground state, 6 H15/2 ), with J–O parameters of the prepared glass samples. Transition 6 H15/2 →
6
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 3/2 F 2 10−20 cm2 4 10−20 cm2 6 10−20 cm2 4 / 6 r.m.s. 6
Wavele-ngth (nm)
1714.4 1294 1097 907 804 756
Energy (cm-1 )
5833 7728 9116 11025 12438 22321
0.5 Dy Ba
1.0 Dy Ba
0.5 Dy Sr
1.0 Dy Sr
fexp
fcal
fexp
fcal
fexp
fcal
fexp
fcal
2.9495 10.429 3.1675 2.342 1.1763 1.0826 6.4331 4.0963 3.4048 1.203 0.8640
3.1383 10.409 0.1334 2.4199 1.1752 0.2077
1.7396 7.6416 2.4002 1.745 0.9019 0.3164 5.4880 2.4694 2.0741 1.190 0.8747
1.9244 7.6234 0.083 1.8178 0.7159 0.1265
2.240 10.26 3.427 2.602 1.172 0.678 5.6636 5.2493 2.7861 1.883 0.8653
2.498 10.24 0.113 2.705 0.962 0.170
2.7017 11.5734 3.6866 2.6537 1.2913 0.4528 8.4804 3.5443 3.1779 1.115 0.8321
2.9463 11.549 0.127 2.7527 1.0969 0.1938
Table 4 – Comparison of Judd–Ofelt parameters (×10−20 cm2 ) in Dy3+ glasses. System
Reference
2
4
6
4 /6
(30-x) (NaPO3 )6 − 30PbO 40 B2 O3 + xDy2 O3 YAl3(BO3 )4 (YAB) + Dy2 O3 (73 x)PbO–18B2 O3 –6Al2 O3 –3WO3 –xDy2 O3 (79-x)B2 O3 + P2 O5 + 10Li2 O + 10ZnO + 1Dy2 O3 (99 – x)Li2 CO3 · xH3 BO3 · 1Dy2 O3 (PbFPDy: P2 O5 + K2 O + Al2 O3 + PbF2 + Na2 O + Dy2 O3 ) 30PbO–25Sb2 O3 –(45−x)B2 O3 –xDy2 O3 (50B2 O3 –30PbO–20SrO–xDy) (50B2 O3 –30PbO–20BaO–xDy)
[20] [21] [8] [22] [23] [24] [25] Present work Present work
6.37 9.49 4.90 2.95 5.41 7.12 5.81 8.48 5.48
0.34 2.77 0.94 1.20 1.89 1.59 1.13 3.54 2.46
2.16 2.01 2.07 1.79 1.92 2.20 2.68 3.17 2.07
0.199 1.378 0.454 0.670 0.984 0.722 1.116 1.910 1.115
Commonly, the parameter 2 is considered to be a metal covalency marker while the parameters 4 and 6 consider to be a host matrix rigidity marker. The values of the 2 of the sample (1.0 Dy Sr) in Table 3 indicate that the Dy–O covalency is strong and the asymmetry is low compared with the other samples. This result is in agreement with the results obtained by Refs. [18,19]. The value of 2 is increase by increasing the ratio of the Dy3+ in the two glasses matrices. The parameters 4 and 6 indicate that the sample (0.5 Dy Sr) is higher rigidity than the other samples and has also a higher spectroscopic quality factor (4 /6 ). The factor (4 /6 ) is a significant laser parameter in expecting the stimulated emission in a laser active media. The trend of the is 2 < 4 < 6 which the common trend and also in agreement with the previous work [14]. Several attempts have been made to investigate the Judd–Ofelt parameters 2 , 4 , and 6 in addition to the factor (4 /6 ). The present study has reported good fit values to the previous studies which reported in Table 4. The calculated refractive indexes at every transition are demonstrated in Table 5. The data from this table can be compared with the data in Table 1 which shows a good fit. One of the most important advantages of the Judd–Ofelt analysis is the prediction of the radiative transition probabil ities A(J, J ) for the electric dipole transitions between excited states and the lower level of the Dy3+ which can be calculated using the parameters via the equation: A(J, J’ ) = ×
n(n2 + 2) 642 e2 × 3 9 3h (2J + 1)
=2, 4, 6
˝ (S, L)J
2
’ ’ ’ 2
U S , L J
(7)
The lifetime of radiative an excited level is calculated by the inverse of the sum of A(J, J ) values calculated overall terminal levels: rad =
1
(8)
A(J, J’ )
The luminescence branching ratio ˇ J, J which, indicates the relative intensities of transitions from the excited, J, state to another level, J , is given by the relation:
ˇ J, J’ =
A(J, J’ )
J’
A(J, J’ )
(9)
The value of the branching ratio indicates the possibility of using the radiative transition band in the laser devices. Table 6 illustrates the values of the branching ratio of the most sensitive radiative transition and their corresponding radiate lifetime. It is apparent from this table that the two transition 6 H11/2 and 6 F11/2 in the demonstrated four samples is a quite possible candidate for using as gain media in 1700 nm and 1300 nm respectively (ˇ ≥ 0.5). the values of ˇ in the rest of the transitions reveal that the not all the transition is high potential for using as gain media except for sample (0.5 Ba Dy) at the transition 6 H7/2 and the samples (1.0 Ba Dy and 1.0 Sr Dy) at the transition 6F5/2. A Highly laser media candidate system was introduced by Vijayakumar et al. [22] using Dy3+ doped Zinc borophosphate glasses.
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Table 5 – Calculated refractive indexes for prepared glass samples. Transition 6 H15/2 →
Ba-Dy 0.5 n
Ba-Dy 1.0 n
Sr-Dy 0.5 n
Sr-Dy 1.0 n
6
1.3589 1.4459 1.5074 1.2064 1.4028 1.4240
1.4881 1.5740 1.6445 1.4173 1.5336 1.5513
1.3798 1.4684 1.5296 1.2410 1.4303 1.4510
1.5216 1.6013 1.6604 1.4425 1.5690 1.5860
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 F3/2 6
Table 6 – Calculated branching ratio (ˇ) and lifetime (, ms) for prepared glass samples. Transition 6 H15/2 →
Ba-Dy 0.5
6
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 F3/2 6
Ba-Dy 1.0
Sr-Dy 0.5
Sr-Dy 1.0
ˇ
(ms)
ˇ
(ms)
ˇ
(ms)
ˇ
(ms)
0.9444 0.9537 0.4263 0.1627 0.6276 0.1749
11.555 1.2466 15.551 0.3706 0.9518 0.7955
0.9094 0.9492 0.3911 0.0671 0.4891 0.1358
13.798 1.2989 17.352 0.1243 0.9250 0.7772
0.9111 0.9487 0.3832 0.1215 0.4409 0.1374
13.3924 1.2023 15.7759 0.2287 0.7708 0.7212
0.9197 0.9477 0.3822 0.1275 0.5013 0.1511
8.4993 0.8095 10.7177 0.1487 0.5754 0.5259
Fig. 5 – Predicted absorption and their corresponding emission for the transitions 6 H11/2 , 6 F11/2 , 6 H7/2 , and 6 F7/2 (a) sample 0.5 Dy Ba, (b) sample 1.0 Dy Ba, (c) sample 0.5 Dy Sr, and (d) sample 1.0 Dy Sr.
The absorption cross section at any transition abs () is given by the equation: abs () = 2.0303
OD() Nl
(10)
where N is the concentration of respective Dy3+ ions for each sample. The corresponding emission cross section at the same transition () is given by:
emis () = abs ()
− hc−1
EZl Zl exp Zu KB T
(11)
where Zl is the partition function for lower levels and Zu is the partition function for upper concerned in the measured optical transition, T is the room temperature and Ezl is the zero line energy for the transition between the lower Stark sublevels of the emitting and the receiving multiples. The values of ( emis ) for the transition 6 F11/2 (1267 nm),which evaluated as hypersensitive transition (HST) in the IR region is about 2.0 × 10−20 for the sample (1.0 Dy Ba) and 2.9 × 10−20 for sample (1.0 Dy Sr).
Fig. 5 illustrates the predicted absorption and their corresponding emission for the transitions 6 F7/2 , 6 F9/2 , 6 F11/2 , and 6H 11/2 in the four samples under investigation. The optical gain coefficient G() is a very important function that helps to estimate the probability of operating laser wavelength using the equation [26,27]: G () = emis () NP − abs () N (1 − P)
(12)
where P is the population inversion rate for laser transitions (4 transitions, N is the concentration of Dy3+ ions. The values of P were taken as 0, 0.1, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 and 1.00. The distribution of the gain profiles for Dy3+ ions are illustrated in Fig. 6a–d. Commonly the function G() is calculated for the most intense emission peak, (at ≈ 1267 nm in our study), but what interesting in these study is calculating of the function G() for the four transitions 6 H11/2 , 6 F11/2 , 6 H7/2 , and 6 F7/2 which have the possibilities to use as operating laser wavelength media or in the optical communications fibers and laser emission wavelengths (ˇ ≥ 0.5).
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Fig. 6 – Predicted gain coefficient G () for the prepared glasses doped with Dy3+ ions (a) sample (0.5 Dy Ba), (b) sample (1.0 Dy Ba), (c) sample (0.5 Dy Sr), and (d) sample (1.0 Dy Sr).
4.
Conclusion
Successfully two glasses compositions (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy) where x = 0. 0.5%, and 1.0% in wt.% ratio, were prepared by melt quenching technique and from the experimental absorption spectra showed the regular transitions of the Dy3+ ions and the bandgap energy in both direct and indirect regimes remain without any significant change in case of the presence of Ba2+ while the band gap decreases then increases with the increase of Dy3+ in case of Sr2+ present. The mean regular transitions 6 F3/2 (748 nm), 6 F5/2 (798 nm), 6F 6 6 6 7/2 (900 nm), F9/2 (1090 nm), F11/2 (1267 nm), and H11/2 (1672 nm) where observed in the absorption spectra. Also, the refractive index obtained from the experimental data agrees with the one obtained from theoretical calculations. The FTIR study confirmed there was no change in the absorption band between the studied samples. The existence of the structural units such as BO3 , BO4 and PO4 and the presence of non-bridging oxygen with increasing Dy3+ ions concentration were identified. The Judd Ofelt calculations reveal that the sample (1.0 Dy Sr) has a strong Dy-O covalency and low asymmetry comparing with the other samples. On the other hand, the parameters 4 and 6 indicate that the sample (0.5 Dy Sr) is higher rigidity than the other samples and has also a higher spectroscopic quality factor (4 /6 ). The obtained
results were in good fit with the previous work. In addition, the results of this study showed that the two transition 6 F11/2 and 6 H11/2 in the demonstrated the four samples is a quite possible candidate for using as gain media in ≈1267 nm and 1672 nm respectively (ˇ ≥ 0.5) in the IR region. On the other hand, the function G() for the four transitions 6 H11/2 , 6 F11/2 , 6 6H 7/2 , and F7/2 in the visible region have the possibilities to use as operating laser wavelength media or in the optical communications fibers and laser emission wavelengths.
Conflicts of interest The authors declare no conflicts of interest.
references
[1] Gautam C, Yadav AK, Singh AK. A review on infrared spectroscopy of borate glasses with effects of different additives. ISRN Ceram 2012:428497, http://dx.doi.org/10.5402/2012/428497, 17 pages. [2] Shaw RR, Breedis JF. Secondary phase separation in lead borate glasses. J Am Ceram Soc 1972;55:422–5, http://dx.doi.org/10.1111/j.1151-2916.1972.tb11326.x. [3] Zhu D, Ray CS, Luo F, Zhou W, Day DE. Melting and phase-separation of lead borate glasses in low gravity drop
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[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
shaft. Ceram Int 2008;34:417–20, http://dx.doi.org/10.1016/j.ceramint.2006.10.014. Xi Y, Xu Z, Hou Z, Liu L, Xu L, Wang W, et al. Second-order optical nonlinearity in bulk PbO/B2O3 glass. Opt Commun 2002;210:367–73, http://dx.doi.org/10.1016/S0030-4018(02)01565-1. Wang M, Liu Q, Liu H, Zhao X. Thermally induced second harmonic generation in PbO-B2O3 glasses. Opt Commun 2007;274:218–22, http://dx.doi.org/10.1016/j.optcom.2007.02.006. Marzouk MA, Elbatal FH, Eisa WH, Ghoneim NA. Comparative spectral and shielding studies of binary borate glasses with the heavy metal oxides SrO, CdO, BaO, PbO or Bi2O3 before and after gamma irradiation. J Non Cryst Solids 2014;387:155–60, http://dx.doi.org/10.1016/j.jnoncrysol.2014.01.002. Pisarska J. Optical properties of lead borate glasses containing Dy3+ ions. J Phys Condens Matter 2009;21, http://dx.doi.org/10.1088/0953-8984/21/28/285101. Pisarska J, Pisarski WA, Ryba-Romanowski W. Laser spectroscopy of Nd3+ and Dy3+ ions in lead borate glasses. Opt Laser Technol 2010;42:805–9, http://dx.doi.org/10.1016/j.optlastec.2009.12.008. Pisarska J. Luminescence behavior of Dy3+ ions in lead borate glasses. Opt Mater (Amst) 2009;31:1784–6, http://dx.doi.org/10.1016/j.optmat.2008.11.028. Vijayakumar M, Marimuthu K. Structural and luminescence properties of Dy3+ doped oxyfluoro-borophosphate glasses for lasing materials and white LEDs. J Alloys Compd 2015;629:230–41, http://dx.doi.org/10.1016/j.jallcom.2014.12.214. Okasha A, Marzouk SY, Hammad AH, Abdelghany AM. Optical character inquest of cobalt containing fluoroborate glass. Optik (Stuttg) 2017;142, http://dx.doi.org/10.1016/j.ijleo.2017.05.088. Dimitrov V, Sakka S. Linear and nonlinear optical properties of simple oxides. II. J Appl Phys 1996;79:1741–5, http://dx.doi.org/10.1063/1.360963. Elbatal FH, Ibrahim S, Abdelghany AM. Optical and FTIR spectra of NdF3-doped borophosphate glasses and effect of gamma irradiation. J Mol Struct 2012;1030:107–12, http://dx.doi.org/10.1016/j.molstruc.2012.02.049. Work R. University of California radiation laboratory. Ind Eng Chem 2012;48, http://dx.doi.org/10.1021/i650564a772, 89A–89A. Ofelt GS. Intensities of crystal spectra of rare-earth ions. J Chem Phys 2005;37:511–20, http://dx.doi.org/10.1063/1.1701366. Weber MJ. Spontaneous emission probabilities and quantum efficiencies for excited states of Pr3+in LaF3. J Chem Phys 1968;48:4774–80, http://dx.doi.org/10.1063/1.1668061.
[17] Jørgensen Chr Klixbüll, Judd BR. Hypersensitive pseudoquadrupole transitions in lanthanides. Mol Phys 2003;10113:1967–76, http://dx.doi.org/10.1080/0026897031000109275. [18] Shamshad L, Rooh G, Kirdsiri K, Srisittipokakun N, Damdee B, Kim HJ, et al. Effect of alkaline earth oxides on the physical and spectroscopic properties of Dy 3 þ - doped Li 2 O-B 2 O 3 glasses for white emitting material application. Opt Mater (Amst) 2017;64:268–75, http://dx.doi.org/10.1016/j.optmat.2016.12.027. [19] Shaaban KS, El-Maaref AA, Abdelawwad M, Saddeek YB, Wilke H, Hillmer H. Spectroscopic properties and Judd-Ofelt analysis of Dy3+ ions in molybdenum borosilicate glasses. J Lumin 2018;196:477–84, http://dx.doi.org/10.1016/j.jlumin.2017.12.041. [20] Kiran N, Suresh Kumar A. White light emission from Dy3+ doped sodium-lead borophosphate glasses under UV light excitation. J Mol Struct 2013;1054–1055:6–11, http://dx.doi.org/10.1016/j.molstruc.2013.09.023. [21] Ryba-Romanowski W, Dominiak-Dzik G, Solarz P, Lisiecki R. Transition intensities and excited state relaxation dynamics of Dy3+ in crystals and glasses: a comparative study. Opt Mater (Amst) 2009;31:1547–54, http://dx.doi.org/10.1016/j.optmat.2009.04.013. [22] Vijayakumar R, Venkataiah G, Marimuthu K. White light simulation and luminescence studies on Dy3+ doped Zinc borophosphate glasses. Phys B Condens Matter 2015;457:287–95, http://dx.doi.org/10.1016/j.physb.2014.10.003. [23] Babu P, Jayasankar CK. Spectroscopic properties of Dy3+ ions in lithium borate and lithium fluoroborate glasses. Opt Mater (Amst) 2000;15:65–79, http://dx.doi.org/10.1016/S0925-3467(00)00015-X. [24] Kesavulu CR, Jayasankar CK. White light emission in Dy3+-doped lead fluorophosphate glasses. Mater Chem Phys 2011;130:1078–85, http://dx.doi.org/10.1016/j.matchemphys.2011.08.037. [25] Chandra Shekhar Reddy M, Appa Rao B, Brik MG, Prabhakar Reddy A, Raghava Rao P, Jayasankar CK, et al. Emission characteristics of Dy3+ ions in lead antimony borate glasses. Appl Phys B Lasers Opt 2012;108:455–61, http://dx.doi.org/10.1007/s00340-012-4983-z. [26] Okasha A, Abdelghany AM, Marzouk SY. Judd–Ofelt analysis of spectroscopic properties of Sm3+ doped P2O5–SrO glasses. J Mater Sci Mater Electron 2017;28:12132–8, http://dx.doi.org/10.1007/s10854-017-7027-y. [27] Philipps JF, Töpfer T, Ebendorff-Heidepriem H, Ehrt D, Sauerbrey R. Spectroscopic and lasing properties of Er3+:Yb3+-doped fluoride phosphate glasses. Appl Phys B Lasers Opt 2001;72:399–405, http://dx.doi.org/10.1007/s003400100515.
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Original Article
The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study Aly Okasha a,∗ , A.M. Abdelghany a,b , S.Y. Marzouk c a b c
Spectroscopy Department, Physics Division, National Research Center, 33 ElBehouth St., Dokki, 12311, Giza, Egypt Basic Science Department, Horus University, International Coastal Rd, New Damietta, Kafr Saad, Damietta, Egypt Basic and Applied Science, Faculty of Engineering, Arab Academy of Science and Technology, Al-Horria, Heliopolis, Cairo, Egypt
a r t i c l e
i n f o
a b s t r a c t
Article history:
Two glasses compositions (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy)
Received 13 September 2019
where x = 0.0.5%, and 1.0% in wt.% ratio were prepared using melt quenching technique
Accepted 12 October 2019
in order to investigate the effect of Ba2+ and Sr2+ ions in Dy3+ ions doped lead borate glass.
Available online xxx
The optical properties such as bandgap and the refractive index distribution were examined using UV–vis-NIR absorption spectroscopy. The FTIR absorption spectra of all prepared
Keywords:
samples were similar except for the metallic bands in the fingerprint region. The obtained
Lead borate glasses
experimental data were compared with theoretical data calculated by Judd–Ofelt framework.
Optical properties
The Judd–Ofelt parameters ( = 2, 4 and 6) were calculated and the trend was 2 < 4 < 6
Judd–Ofelt theory
which is the common trend. The experimental oscillator strength (fexp ), the calculated oscillator strength (fcal ), the estimated refractive indexes (n) at each transition, the lifetime of radiative transitions (), the branching ratio (ˇ), the absorption cross-section ( abs ()) and the emission cross-section ( emis ()) were also estimated and discussed. The optical gain coefficient (G()) was calculated not only for the most intense emission transition but also other emission peaks. The obtained results indicated that the prepared samples are promising materials for laser emission and optical communication applications. © 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1.
∗
Introduction
During the last two decades, the using of the glasses material attracts enormous attention. Among the glasses material the borate glass containing transition metals, such as ZnO, PbO, TeO2 Bi2 O3 , MgO, CaO, SrO, and BaO, attracts great attention
Corresponding author. E-mail: [email protected] (A. Okasha). https://doi.org/10.1016/j.jmrt.2019.10.029 2238-7854/© 2019 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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due to the ability to tailoring its properties to fit special applications. Recent developments in the field of borate glasses have led to a renewed interest in the fields of leasing and Opto-communications materials, optical filters and photonic devices [1]. Several attempts have been made to investigate the modified lead borate glasses materials. In that manner, Shaw et al. [2] and Zuh et al. [3] studied the phase separation of the lead borate glasses. Besides, Xi et al. [4] and Wang et al. [5], were reported that the ratio of PbO/B2 O3 is playing an essential role in the structure of the glass network. Adding heavy metal oxides, such as BaO and SrO, to the lead borate glasses is one of the most widely used methods to tailoring the optical properties and radiation shielding of the glasses [6]. The great change in the optical properties of the glasses was experienced by adding a rare earth element to the structure of the glasses. Pisarska et al. [7] studied the lead borate glass contains Dy3+ ions and investigates the luminance properties in the presence of Al2 O3 and WoO3 . In their study, the absorption and luminance properties of the glass were investigated and compared by the estimated theoretical values using Judd–Ofelt (J–O) calculation. The same group studied the Dy3+ luminance transitions 6 H11/2 at 662 nm, 6 H113/2 at 573 nm and 6H 15/2 at 480 nm [8]. In addition, the yellow/blue luminescence of trivalent Dy was studied as a function of the B2 O3 /PbO ratios in the presence of Cr3+ as an alkaline metal [9]. So far, however, The research to date has tended to focus on investigation the luminance properties of lead borate glasses containing Dy3+ in the visible spectral region rather than the IR spectral region [7–9]. In the present study two glass series were prepared, (50B2 O3 –30PbO–20BaO–XDy), and (50B2 O3 –30PbO–20SrO–xDy) where x = 0, 0.5% and 1%. The study has tended to focus on studying the optical properties of the lead borate glass containing Dy3+ ions in the presence of two alkali earth metal oxides (BaO and SrO) in both the visible and the IR region. The experimental data will compare with the theoretical data obtained from the J–O framework to estimate the absorption and luminance characteristics to investigate the suitability of the studied glasses in the optical communication fiber.
2.
Experimental details
2.1.
Samples preparation
Two glass systems of nominal composition (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy) where x = 0.0.5%, and 1.0% in wt.% ratio, were prepared using pure chemical reagents including orthoboric Boric acid, H3 BO3 (Laboratory Rasayan Sd Fine-Chem. Limited), lead Oxide, PbO (Sisco research Lab. India), Barium Oxide BaO, and Strontium Oxide, SrO from (Panreac Quimica SA, Espana), Dy3 O2 (99.99%, Aldrich Chemical Co) which were used as received without any farther purifications. The melt quenching technique was used in glass synthesis under atmospheric conditions. In the typical method, weighted materials were mixed carefully and melted at 1100 ◦ C using an electric furnace for about 2 h in platinum crucibles. In the next step, samples were cast in a stainless steel mold and transferred into a muffle furnace and kept at 400◦ C for annealing for 2 h, then the furnace was left
Fig. 1 – UV–vis-NIR absorption spectra.
to cool down to the room temperature overnight. Six samples were cut, polished and smoothed in 1 cm × 2 cm (±0.1 mm) rectangular shape with 2 mm (±0.1 mm) thickness. Finally, the samples named (base Ba), (0.5 Dy Ba), (1.0 Dy Ba), (Base Sr), (0.5 Dy Sr) and (1.0 Dy Sr) as shown in Table 1.
2.2.
Glass density measurements
The traditional Archimedes method was used to determine the glass densities at room temperature by weighing the samples in both air (wtair ) and weighed in submerged xylene (wtimmeresed ). The density of the glass (D) is estimated from the equation: D
g cm3
=
wtair × 0.863 wtair − wtxylene
(1)
where, 0.863 represents the xylene density in units of g/cm3 . All measurements were performed in triplicate different samples for error elimination and estimation. The results of the density measurements were illustrated in Table 1.
2.3.
Optical absorption and infrared measurements
The absorption spectra of the samples under investigation were carried out using (JASCO model V730 Japan) spectrophotometer and the results were illustrate in Fig. 1. While, the FTIR spectra of the samples measured using (Bruker Model Vertex 70) Spectrometer using the KBr disc technique in the spectral range 4000–400 cm−1 . The FTIR spectra were demonstrated in Fig. 4.
3.
Results and discussion
3.1.
Optical absorption
The absorption spectra in the UV–vis-IR spectral range from 300 nm to 2000 nm were illustrated in Fig. 1 the inset shows the sample (1.0 Dy Sr) focused on the range from 425 nm to 550 nm headed for identifying the two absorption peaks at
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Table 1 – Glass symbols, direct and indirect optical band gap, Eg; glass density, D; and the refractive index n. Sample symbol
Density, D (g/cm3 ) ±0.018
Direct optical band gap, ± 0.05 (eV)
Indirect optical band gap,± 0.05 (eV)
n
Base Ba 0.5 Dy Ba 1.0 Dy Ba Base Sr 0.5 Dy Sr 1.0 Dy Sr
4.87 4.80 4.76 4.78 4.73 4.63
2.91 2.91 2.91 2.91 3.00 3.79
3.42 3.41 3.43 3.51 3.53 3.41
1.43 1.43 1.43 1.43 1.42 1.37
Fig. 2 – (a) Direct band gap for allowed transitions, (b) indirect band gab for allowed transitions.
Fig. 3 – (a) Reflectance distribution and (b) represent the refractive index distribution.
448 nm and 476 nm which corresponding to the transitions 4I 4 15/2 , F15/2 respectively. In addition, the mean figure showed other means six peaks at 748 nm, 798 nm, 900 nm, 1090 nm, 1267 nm and 1672 nm which are corresponding to the transitions, 6 F3/2 , 6 F5/2 , 6 F7/2 , 6 F9/2 , 6 F11/2 , and 6 H11/2 respectively. The intensities of all transitions increase by increasing both Ba3+ and Sr3+ in the samples. The same results were reported by Marimuthu et al. [10]. They observed that the transitions 4 I15/2 , 4F 3+ ions are relativity weak comparing with the 15/2 of the Dy other transitions due to the strong host lattice absorption in the UV region.
3.2.
Calculations of the optical band gap
The fundamental optical band gap (Eopt ) of the two studied glasses systems has no sharp edges as shown in Fig. 1. However, by using Beer–Lambert–Bouguer law, with simple
modification the optical band gap energy calculated thought the equation [11]: m
(∝ hω) = C (hω − Eopt )
(2)
where m take values of ½ or 2 for direct allowed, indirect allowed transitions respectively, C is a constant and ˛ is the absorption coefficient. The optical band gap values were obtained by extrapolating the linear region of the plot of Eq. (2) for m= ½ was illustrated in Fig. 2-a, while the fitted one for m = 2 was illustrated in Fig. 2-b. It is observed that the value of the optical band gap in case of direct allowed or indirect allowed transitions for the Ba system glass nearly does not change with increase the Ba, and the value is around 2.97 and 3.41 eV respectively. On the other hand, for Sr system, the direct-allowed decrease from 3.11 to 2.88 eV, and indirect allowed transitions band gaps decreases from 3.50 to 3.41 by
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Table 2 – FTIR band position and assignments. IR peak position (cm−1 )
Peak assignment
∼460 ∼617 ∼694 ∼944 ∼1214
Vibrations of metal cations Ba2+ or Sr2+ Binding O—B—O Combination vibration of BO4 and PbO4 groups B—O—B linkage Asymmetric stretching of B—O bonds from orthoborate groups Presence of pyriborate, orthoborate groups containing BO3 Hydrogen bonding OH group
∼1340 ∼2923 ∼3430
3.4.
Fig. 4 – FTIR absorption spectra for all glass samples.
increasing the Sr content. However, directly allowed or indirect allowed band gap increase by increasing the Dy3+ in the samples. These results are in agreement with Marimuthu et al. [10] findings. The optical band gap energies have been used to determine the different values of refractive index (n) by using Dimitrov and Sakka relation [12].
− 1) =1− (n2 + 2) (n2
from an initial state, (S, L) J, to final excited state, S , L J , is depending on the Judd–Ofelt parameters ( = 2,4,6) and is given by:
fcal (S, L) J; S’ , L’ J’ =
˝ (S, L)J
82 mc (n2 + 2) × 9n 3h(2J + 1)
’ ’ ’ 2
U S , L J
2
(4)
=2, 4, 6
(3)
where Eg is the direct optical band gap for allowed transitions. The refractive index values enlisted in Table 1. The reflectance distribution and the refractive index distribution are shown in Fig. 3-a and -b). The two figures indicate the sensitivity of the reflectance distribution and the refractive index distribution to the different transitions of Dy3+ .
3.3.
The calculations of the radioactive transitions properties illustrated by Judd–Ofelt theory [14,15] is important to understand the optical properties of the Dy3+ doped glasses in both the two matrix which contain Ba or Sr. The calculation in this work suggest that the calculated oscillator strength of an electronic dipole absorption transition, fcal (S, L) J; S , L J ,
× Eg 20
Judd–Ofelt calculations
FTIR absorption spectral data
FTIR absorption spectra are demonstrated in Fig. 4. The network observed in the studied two glasses systems are in the main three infrared bands. The band around ∼794 cm−1 which related to the combination of both phosphate and borate groups (BO3 and BO4 ) with the first phosphate partner. The band <750–1150 cm−1 related vibrations of both non-bridging PO2 groups and the stretching vibrations of BO3 groups. The band <1150–1600 cm−1 related to (OH), POH, and BOH vibrations. In addition to the vibrations of metallic cations at about 460 cm−1 . The peak at about 2920 related to the hydrogen bonding, while the peak at about 3400 related to the OH group. There was no change in the absorption band between the studied samples. The previous study has reported the same results using NF3 phosphate glasses [13]. The detailed band assignment are showed in the Table 2.
where m is the electron mass, h is the Plank’s constant, is the wavelength, n is the refractive index of the glass,
and U is the doubly reduced matrix of the unit tensor obtained from Weber [16] were applied respectively. By applying the samples parameters (e, l, N, and OD()) the experimental oscillator strength of an electronic dipole absorption transition fexp is given by:
fexp
mc2 = 2.303 lNe2
OD () d d2
(5)
where e is the electron charge, N is the number of active ions per unit volume, l is the sample thickness, and OD() is the optical density. The Judd–Ofelt parameters ( = 2,4,6) calculated using the least squares fitting method (r.m.s.) according to the selection role |S| = 0, |L|≤ 2, |J|≤ 2 [17]. The fitting accuracy between the calculated and the experimental parameters was estimated using the equation:
r.m.s. =
(f
− fmeas )2 P−3
calc
P
12 (6)
where P is the number of observed transitions on the absorption spectrum. However, the values of r.m.s. is small and the values of fcal and fexp , is closed to each other. The results of the fcal , fexp , ˝ and r.m.s. are illustrated in Table 3.
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Table 3 – Calculated (fcal ) and (fexp ) experimental oscillator strengths along (from the ground state, 6 H15/2 ), with J–O parameters of the prepared glass samples. Transition 6 H15/2 →
6
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 3/2 F 2 10−20 cm2 4 10−20 cm2 6 10−20 cm2 4 / 6 r.m.s. 6
Wavele-ngth (nm)
1714.4 1294 1097 907 804 756
Energy (cm-1 )
5833 7728 9116 11025 12438 22321
0.5 Dy Ba
1.0 Dy Ba
0.5 Dy Sr
1.0 Dy Sr
fexp
fcal
fexp
fcal
fexp
fcal
fexp
fcal
2.9495 10.429 3.1675 2.342 1.1763 1.0826 6.4331 4.0963 3.4048 1.203 0.8640
3.1383 10.409 0.1334 2.4199 1.1752 0.2077
1.7396 7.6416 2.4002 1.745 0.9019 0.3164 5.4880 2.4694 2.0741 1.190 0.8747
1.9244 7.6234 0.083 1.8178 0.7159 0.1265
2.240 10.26 3.427 2.602 1.172 0.678 5.6636 5.2493 2.7861 1.883 0.8653
2.498 10.24 0.113 2.705 0.962 0.170
2.7017 11.5734 3.6866 2.6537 1.2913 0.4528 8.4804 3.5443 3.1779 1.115 0.8321
2.9463 11.549 0.127 2.7527 1.0969 0.1938
Table 4 – Comparison of Judd–Ofelt parameters (×10−20 cm2 ) in Dy3+ glasses. System
Reference
2
4
6
4 /6
(30-x) (NaPO3 )6 − 30PbO 40 B2 O3 + xDy2 O3 YAl3(BO3 )4 (YAB) + Dy2 O3 (73 x)PbO–18B2 O3 –6Al2 O3 –3WO3 –xDy2 O3 (79-x)B2 O3 + P2 O5 + 10Li2 O + 10ZnO + 1Dy2 O3 (99 – x)Li2 CO3 · xH3 BO3 · 1Dy2 O3 (PbFPDy: P2 O5 + K2 O + Al2 O3 + PbF2 + Na2 O + Dy2 O3 ) 30PbO–25Sb2 O3 –(45−x)B2 O3 –xDy2 O3 (50B2 O3 –30PbO–20SrO–xDy) (50B2 O3 –30PbO–20BaO–xDy)
[20] [21] [8] [22] [23] [24] [25] Present work Present work
6.37 9.49 4.90 2.95 5.41 7.12 5.81 8.48 5.48
0.34 2.77 0.94 1.20 1.89 1.59 1.13 3.54 2.46
2.16 2.01 2.07 1.79 1.92 2.20 2.68 3.17 2.07
0.199 1.378 0.454 0.670 0.984 0.722 1.116 1.910 1.115
Commonly, the parameter 2 is considered to be a metal covalency marker while the parameters 4 and 6 consider to be a host matrix rigidity marker. The values of the 2 of the sample (1.0 Dy Sr) in Table 3 indicate that the Dy–O covalency is strong and the asymmetry is low compared with the other samples. This result is in agreement with the results obtained by Refs. [18,19]. The value of 2 is increase by increasing the ratio of the Dy3+ in the two glasses matrices. The parameters 4 and 6 indicate that the sample (0.5 Dy Sr) is higher rigidity than the other samples and has also a higher spectroscopic quality factor (4 /6 ). The factor (4 /6 ) is a significant laser parameter in expecting the stimulated emission in a laser active media. The trend of the is 2 < 4 < 6 which the common trend and also in agreement with the previous work [14]. Several attempts have been made to investigate the Judd–Ofelt parameters 2 , 4 , and 6 in addition to the factor (4 /6 ). The present study has reported good fit values to the previous studies which reported in Table 4. The calculated refractive indexes at every transition are demonstrated in Table 5. The data from this table can be compared with the data in Table 1 which shows a good fit. One of the most important advantages of the Judd–Ofelt analysis is the prediction of the radiative transition probabil ities A(J, J ) for the electric dipole transitions between excited states and the lower level of the Dy3+ which can be calculated using the parameters via the equation: A(J, J’ ) = ×
n(n2 + 2) 642 e2 × 3 9 3h (2J + 1)
=2, 4, 6
˝ (S, L)J
2
’ ’ ’ 2
U S , L J
(7)
The lifetime of radiative an excited level is calculated by the inverse of the sum of A(J, J ) values calculated overall terminal levels: rad =
1
(8)
A(J, J’ )
The luminescence branching ratio ˇ J, J which, indicates the relative intensities of transitions from the excited, J, state to another level, J , is given by the relation:
ˇ J, J’ =
A(J, J’ )
J’
A(J, J’ )
(9)
The value of the branching ratio indicates the possibility of using the radiative transition band in the laser devices. Table 6 illustrates the values of the branching ratio of the most sensitive radiative transition and their corresponding radiate lifetime. It is apparent from this table that the two transition 6 H11/2 and 6 F11/2 in the demonstrated four samples is a quite possible candidate for using as gain media in 1700 nm and 1300 nm respectively (ˇ ≥ 0.5). the values of ˇ in the rest of the transitions reveal that the not all the transition is high potential for using as gain media except for sample (0.5 Ba Dy) at the transition 6 H7/2 and the samples (1.0 Ba Dy and 1.0 Sr Dy) at the transition 6F5/2. A Highly laser media candidate system was introduced by Vijayakumar et al. [22] using Dy3+ doped Zinc borophosphate glasses.
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Table 5 – Calculated refractive indexes for prepared glass samples. Transition 6 H15/2 →
Ba-Dy 0.5 n
Ba-Dy 1.0 n
Sr-Dy 0.5 n
Sr-Dy 1.0 n
6
1.3589 1.4459 1.5074 1.2064 1.4028 1.4240
1.4881 1.5740 1.6445 1.4173 1.5336 1.5513
1.3798 1.4684 1.5296 1.2410 1.4303 1.4510
1.5216 1.6013 1.6604 1.4425 1.5690 1.5860
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 F3/2 6
Table 6 – Calculated branching ratio (ˇ) and lifetime (, ms) for prepared glass samples. Transition 6 H15/2 →
Ba-Dy 0.5
6
H11/2 F11/2 6 H7/2 6 F7/2 6 F5/2 6 F3/2 6
Ba-Dy 1.0
Sr-Dy 0.5
Sr-Dy 1.0
ˇ
(ms)
ˇ
(ms)
ˇ
(ms)
ˇ
(ms)
0.9444 0.9537 0.4263 0.1627 0.6276 0.1749
11.555 1.2466 15.551 0.3706 0.9518 0.7955
0.9094 0.9492 0.3911 0.0671 0.4891 0.1358
13.798 1.2989 17.352 0.1243 0.9250 0.7772
0.9111 0.9487 0.3832 0.1215 0.4409 0.1374
13.3924 1.2023 15.7759 0.2287 0.7708 0.7212
0.9197 0.9477 0.3822 0.1275 0.5013 0.1511
8.4993 0.8095 10.7177 0.1487 0.5754 0.5259
Fig. 5 – Predicted absorption and their corresponding emission for the transitions 6 H11/2 , 6 F11/2 , 6 H7/2 , and 6 F7/2 (a) sample 0.5 Dy Ba, (b) sample 1.0 Dy Ba, (c) sample 0.5 Dy Sr, and (d) sample 1.0 Dy Sr.
The absorption cross section at any transition abs () is given by the equation: abs () = 2.0303
OD() Nl
(10)
where N is the concentration of respective Dy3+ ions for each sample. The corresponding emission cross section at the same transition () is given by:
emis () = abs ()
− hc−1
EZl Zl exp Zu KB T
(11)
where Zl is the partition function for lower levels and Zu is the partition function for upper concerned in the measured optical transition, T is the room temperature and Ezl is the zero line energy for the transition between the lower Stark sublevels of the emitting and the receiving multiples. The values of ( emis ) for the transition 6 F11/2 (1267 nm),which evaluated as hypersensitive transition (HST) in the IR region is about 2.0 × 10−20 for the sample (1.0 Dy Ba) and 2.9 × 10−20 for sample (1.0 Dy Sr).
Fig. 5 illustrates the predicted absorption and their corresponding emission for the transitions 6 F7/2 , 6 F9/2 , 6 F11/2 , and 6H 11/2 in the four samples under investigation. The optical gain coefficient G() is a very important function that helps to estimate the probability of operating laser wavelength using the equation [26,27]: G () = emis () NP − abs () N (1 − P)
(12)
where P is the population inversion rate for laser transitions (4 transitions, N is the concentration of Dy3+ ions. The values of P were taken as 0, 0.1, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 and 1.00. The distribution of the gain profiles for Dy3+ ions are illustrated in Fig. 6a–d. Commonly the function G() is calculated for the most intense emission peak, (at ≈ 1267 nm in our study), but what interesting in these study is calculating of the function G() for the four transitions 6 H11/2 , 6 F11/2 , 6 H7/2 , and 6 F7/2 which have the possibilities to use as operating laser wavelength media or in the optical communications fibers and laser emission wavelengths (ˇ ≥ 0.5).
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
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Fig. 6 – Predicted gain coefficient G () for the prepared glasses doped with Dy3+ ions (a) sample (0.5 Dy Ba), (b) sample (1.0 Dy Ba), (c) sample (0.5 Dy Sr), and (d) sample (1.0 Dy Sr).
4.
Conclusion
Successfully two glasses compositions (50B2 O3 –30PbO–20SrO–xDy) and (50B2 O3 –30PbO–20BaO–xDy) where x = 0. 0.5%, and 1.0% in wt.% ratio, were prepared by melt quenching technique and from the experimental absorption spectra showed the regular transitions of the Dy3+ ions and the bandgap energy in both direct and indirect regimes remain without any significant change in case of the presence of Ba2+ while the band gap decreases then increases with the increase of Dy3+ in case of Sr2+ present. The mean regular transitions 6 F3/2 (748 nm), 6 F5/2 (798 nm), 6F 6 6 6 7/2 (900 nm), F9/2 (1090 nm), F11/2 (1267 nm), and H11/2 (1672 nm) where observed in the absorption spectra. Also, the refractive index obtained from the experimental data agrees with the one obtained from theoretical calculations. The FTIR study confirmed there was no change in the absorption band between the studied samples. The existence of the structural units such as BO3 , BO4 and PO4 and the presence of non-bridging oxygen with increasing Dy3+ ions concentration were identified. The Judd Ofelt calculations reveal that the sample (1.0 Dy Sr) has a strong Dy-O covalency and low asymmetry comparing with the other samples. On the other hand, the parameters 4 and 6 indicate that the sample (0.5 Dy Sr) is higher rigidity than the other samples and has also a higher spectroscopic quality factor (4 /6 ). The obtained
results were in good fit with the previous work. In addition, the results of this study showed that the two transition 6 F11/2 and 6 H11/2 in the demonstrated the four samples is a quite possible candidate for using as gain media in ≈1267 nm and 1672 nm respectively (ˇ ≥ 0.5) in the IR region. On the other hand, the function G() for the four transitions 6 H11/2 , 6 F11/2 , 6 6H 7/2 , and F7/2 in the visible region have the possibilities to use as operating laser wavelength media or in the optical communications fibers and laser emission wavelengths.
Conflicts of interest The authors declare no conflicts of interest.
references
[1] Gautam C, Yadav AK, Singh AK. A review on infrared spectroscopy of borate glasses with effects of different additives. ISRN Ceram 2012:428497, http://dx.doi.org/10.5402/2012/428497, 17 pages. [2] Shaw RR, Breedis JF. Secondary phase separation in lead borate glasses. J Am Ceram Soc 1972;55:422–5, http://dx.doi.org/10.1111/j.1151-2916.1972.tb11326.x. [3] Zhu D, Ray CS, Luo F, Zhou W, Day DE. Melting and phase-separation of lead borate glasses in low gravity drop
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029
JMRTEC-1006; No. of Pages 8
8
ARTICLE IN PRESS j m a t e r r e s t e c h n o l . 2 0 1 9;x x x(x x):xxx–xxx
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
shaft. Ceram Int 2008;34:417–20, http://dx.doi.org/10.1016/j.ceramint.2006.10.014. Xi Y, Xu Z, Hou Z, Liu L, Xu L, Wang W, et al. Second-order optical nonlinearity in bulk PbO/B2O3 glass. Opt Commun 2002;210:367–73, http://dx.doi.org/10.1016/S0030-4018(02)01565-1. Wang M, Liu Q, Liu H, Zhao X. Thermally induced second harmonic generation in PbO-B2O3 glasses. Opt Commun 2007;274:218–22, http://dx.doi.org/10.1016/j.optcom.2007.02.006. Marzouk MA, Elbatal FH, Eisa WH, Ghoneim NA. Comparative spectral and shielding studies of binary borate glasses with the heavy metal oxides SrO, CdO, BaO, PbO or Bi2O3 before and after gamma irradiation. J Non Cryst Solids 2014;387:155–60, http://dx.doi.org/10.1016/j.jnoncrysol.2014.01.002. Pisarska J. Optical properties of lead borate glasses containing Dy3+ ions. J Phys Condens Matter 2009;21, http://dx.doi.org/10.1088/0953-8984/21/28/285101. Pisarska J, Pisarski WA, Ryba-Romanowski W. Laser spectroscopy of Nd3+ and Dy3+ ions in lead borate glasses. Opt Laser Technol 2010;42:805–9, http://dx.doi.org/10.1016/j.optlastec.2009.12.008. Pisarska J. Luminescence behavior of Dy3+ ions in lead borate glasses. Opt Mater (Amst) 2009;31:1784–6, http://dx.doi.org/10.1016/j.optmat.2008.11.028. Vijayakumar M, Marimuthu K. Structural and luminescence properties of Dy3+ doped oxyfluoro-borophosphate glasses for lasing materials and white LEDs. J Alloys Compd 2015;629:230–41, http://dx.doi.org/10.1016/j.jallcom.2014.12.214. Okasha A, Marzouk SY, Hammad AH, Abdelghany AM. Optical character inquest of cobalt containing fluoroborate glass. Optik (Stuttg) 2017;142, http://dx.doi.org/10.1016/j.ijleo.2017.05.088. Dimitrov V, Sakka S. Linear and nonlinear optical properties of simple oxides. II. J Appl Phys 1996;79:1741–5, http://dx.doi.org/10.1063/1.360963. Elbatal FH, Ibrahim S, Abdelghany AM. Optical and FTIR spectra of NdF3-doped borophosphate glasses and effect of gamma irradiation. J Mol Struct 2012;1030:107–12, http://dx.doi.org/10.1016/j.molstruc.2012.02.049. Work R. University of California radiation laboratory. Ind Eng Chem 2012;48, http://dx.doi.org/10.1021/i650564a772, 89A–89A. Ofelt GS. Intensities of crystal spectra of rare-earth ions. J Chem Phys 2005;37:511–20, http://dx.doi.org/10.1063/1.1701366. Weber MJ. Spontaneous emission probabilities and quantum efficiencies for excited states of Pr3+in LaF3. J Chem Phys 1968;48:4774–80, http://dx.doi.org/10.1063/1.1668061.
[17] Jørgensen Chr Klixbüll, Judd BR. Hypersensitive pseudoquadrupole transitions in lanthanides. Mol Phys 2003;10113:1967–76, http://dx.doi.org/10.1080/0026897031000109275. [18] Shamshad L, Rooh G, Kirdsiri K, Srisittipokakun N, Damdee B, Kim HJ, et al. Effect of alkaline earth oxides on the physical and spectroscopic properties of Dy 3 þ - doped Li 2 O-B 2 O 3 glasses for white emitting material application. Opt Mater (Amst) 2017;64:268–75, http://dx.doi.org/10.1016/j.optmat.2016.12.027. [19] Shaaban KS, El-Maaref AA, Abdelawwad M, Saddeek YB, Wilke H, Hillmer H. Spectroscopic properties and Judd-Ofelt analysis of Dy3+ ions in molybdenum borosilicate glasses. J Lumin 2018;196:477–84, http://dx.doi.org/10.1016/j.jlumin.2017.12.041. [20] Kiran N, Suresh Kumar A. White light emission from Dy3+ doped sodium-lead borophosphate glasses under UV light excitation. J Mol Struct 2013;1054–1055:6–11, http://dx.doi.org/10.1016/j.molstruc.2013.09.023. [21] Ryba-Romanowski W, Dominiak-Dzik G, Solarz P, Lisiecki R. Transition intensities and excited state relaxation dynamics of Dy3+ in crystals and glasses: a comparative study. Opt Mater (Amst) 2009;31:1547–54, http://dx.doi.org/10.1016/j.optmat.2009.04.013. [22] Vijayakumar R, Venkataiah G, Marimuthu K. White light simulation and luminescence studies on Dy3+ doped Zinc borophosphate glasses. Phys B Condens Matter 2015;457:287–95, http://dx.doi.org/10.1016/j.physb.2014.10.003. [23] Babu P, Jayasankar CK. Spectroscopic properties of Dy3+ ions in lithium borate and lithium fluoroborate glasses. Opt Mater (Amst) 2000;15:65–79, http://dx.doi.org/10.1016/S0925-3467(00)00015-X. [24] Kesavulu CR, Jayasankar CK. White light emission in Dy3+-doped lead fluorophosphate glasses. Mater Chem Phys 2011;130:1078–85, http://dx.doi.org/10.1016/j.matchemphys.2011.08.037. [25] Chandra Shekhar Reddy M, Appa Rao B, Brik MG, Prabhakar Reddy A, Raghava Rao P, Jayasankar CK, et al. Emission characteristics of Dy3+ ions in lead antimony borate glasses. Appl Phys B Lasers Opt 2012;108:455–61, http://dx.doi.org/10.1007/s00340-012-4983-z. [26] Okasha A, Abdelghany AM, Marzouk SY. Judd–Ofelt analysis of spectroscopic properties of Sm3+ doped P2O5–SrO glasses. J Mater Sci Mater Electron 2017;28:12132–8, http://dx.doi.org/10.1007/s10854-017-7027-y. [27] Philipps JF, Töpfer T, Ebendorff-Heidepriem H, Ehrt D, Sauerbrey R. Spectroscopic and lasing properties of Er3+:Yb3+-doped fluoride phosphate glasses. Appl Phys B Lasers Opt 2001;72:399–405, http://dx.doi.org/10.1007/s003400100515.
Please cite this article in press as: Okasha A, et al. The influence of Ba2+ and Sr2+ ions with the Dy3+ ions on the optical properties of lead borate glasses: experimental and Judd–Ofelt comparative study. J Mater Res Technol. 2019. https://doi.org/10.1016/j.jmrt.2019.10.029