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Nd-doped oxyfluoroborate glasses and glass-ceramics for NIR laser applications
Journal of Alloys and Compounds 451 (2008) 223–225
Nd-doped oxyfluoroborate glasses and glass-ceramics for NIR laser applications J. Pisarska a,∗ , W. Ryba-Romanowski b , G. Dominiak-Dzik b , T. Goryczka c , W.A. Pisarski c a
Silesian University of Technology, Department of Materials Science, Krasi´nskiego 8, 40-019 Katowice, Poland b Institute of Low Temperature and Structure Research, Wrocław, Poland c University of Silesia, Institute of Materials Science, Katowice, Poland Available online 18 April 2007
Abstract Fluorescence at 1.06 m due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 glass system has been registered and some laser parameters for Nd3+ ions have been evaluated. The Nd-doped oxyfluoroborate glasses have been investigated as a function of PbF2 concentration and thermal treatment. The fluorescence decays from 4 F3/2 excited state of Nd3+ ions are independent on PbF2 concentration. The orthorhombic PbF2 phase has been identified for Nd-doped transparent glass-ceramics obtained after thermal treatment. © 2007 Elsevier B.V. All rights reserved. Keywords: Oxyfluoroborate glass; Glass-ceramics; Neodymium ions; Luminescence
1. Introduction Neodymium is one of the most widely studied luminescent ions emitting light especially for laser devices using the 4 F –4 I 3/2 11/2 transition at 1.06 m. Several works have been devoted to study Nd-doped optical glasses and crystals, which have attracted much attention in the design of near-infrared solidstate lasers. However, only a few works report on laser properties of Nd3+ ions in transparent oxyfluoride glass-ceramics, because Nd3+ ions do not exist in important amounts into crystalline phase. In this optical system, rare earth ions usually are incorporated in fluoride nano- or micro-crystals embedded into glassy oxide matrix. Moreover, some results obtained for transparent oxyfluoride glass-ceramics indicate that Nd3+ ions are more difficult to be incorporated into crystalline phase than other rare earth ions like Er3+ or Tm3+ . Optical properties [1] and upconversion luminescence [2] of Nd3+ in oxyfluoride glasses and transparent glass-ceramics have been reported, which were obtained by different preparation methods. Controlled crystallization (devitrification) and fluorescence properties of Nd3+ ions due to main 4 F3/2 –4 I11/2 laser transition have been examined for transparent oxyfluoride glass-ceramics containing -PbF2 [3] or CaF2 [4] phases. ∗
Corresponding author. E-mail address: [email protected] (J. Pisarska).
0925-8388/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2007.04.167
In our previous work, the Judd–Ofelt analysis and spectroscopic properties of Nd3+ ions in B2 O3 –PbO–Al2 O3 –WO3 glass systems were studied [5]. Presented work is concerned with fluorescence due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses and glass-ceramics. Optical properties [6] and up-conversion losses [7] in Nd3+ doped lead fluoroborate glasses have been examined in detail by Courrol et al. However, no information is available on Nd-doped lead fluoroborate glasses, in which PbO is partially or totally replaced by PbF2 , or during controlled crystallization. It is interesting to see how PbF2 concentration and thermal treatment influence on glass properties and Nd3+ fluorescence in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 –NdF3 system. 2. Experimental techniques Glasses in 18B2 O3 –xPbF2 –(72 − x)PbO–6Al2 O3 –3WO3 –1NdF3 (in wt%) systems (where x = 9, 18, 36, 54, 72) were prepared. Anhydrous oxides and lead fluoride (99.99% purity, Aldrich) were used as starting materials. Homogeneous mixture was heated in a protective atmosphere of dried argon. Glasses were melted at 850 ◦ C in Pt crucibles, then poured into preheated copper moulds and annealed below the glass transition temperature. After this procedure, the samples were slowly cooled to the room temperature. Transparent glassy plates were obtained in thickness of about 2 mm. Selected transparent oxyfluoride glass-ceramics were obtained by thermal treatment of the precursor glasses at their corresponding crystallization temperatures, determined by Perkin Elmer differential scanning calorimeter (DSC). The X-ray diffraction was used to verify the devitrification of the glasses. The XRD patterns were carried out using INEL diffractometer with Cu K␣ radiation in 2θ
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J. Pisarska et al. / Journal of Alloys and Compounds 451 (2008) 223–225
ranges 0–120◦ . The diffractometer is equipped with curved position sensitive detector CPS 120 which allows for data collection in 2θ range 0–120◦ . Luminescence was recorded with a Continuum Model Surelite I optical parametric oscillator pumped by a third harmonic of a Nd:YAG laser. Luminescence was dispersed by a 1 m double grating monochromator and detected with a photomultiplier with S-20 spectral response. Luminescence spectra were recorded using a Stanford SRS 250 boxcar integrator controlled by a computer. Luminescence decay curves were recorded and stored by a Tektronix TDS 3052 oscilloscope. All measurements were carried out at room temperature.
3. Results and discussion 3.1. Influence of PbF2 concentration on glass properties and Nd3+ fluorescence Nd3+
Fluorescence properties of ions in lead fluoroborate glasses have been investigated, where PbO was partially or totally replaced by PbF2 . Three emission bands at 904, 1061 and 1335 nm were registered, which can be assigned to 4 F3/2 –4 I9/2 , 4 F –4 I 4 4 3+ ions, respec3/2 11/2 and F3/2 – I13/2 transitions of Nd tively. One of them, fluorescent band at 1061 nm due to main 4 F –4 I 3+ ions in lead fluoroborate 3/2 11/2 laser transition of Nd glasses is presented in Fig. 1. Inset shows influence of PbF2 concentration on fluorescence decay from 4 F3/2 excited state of Nd3+ ions. All transitions from 4 F3/2 state of Nd3+ ions are also schematized. Any significant changes in values of 4 F3/2 fluorescence lifetime have been observed with replacement of PbO by PbF2 . Quite different situation takes place for NIR luminescence at 1.53 m due to main 4 I13/2 –4 I15/2 laser transition of Er3+ ions in lead fluoroborate glasses, where the 4 I13/2 lifetime significantly increases with increasing PbF2 content [8]. In contrast to Er3+ ions, the 4 F3/2 measured lifetime of Nd3+ ions is close to about 86 s and its value is independent on PbF2 concentration in lead fluoroborate glasses. Additionally, some laser parameters like emission cross-section (σ em = 3.58 × 10−20 cm2 ), radiative
Fig. 1. Fluorescence at 1061 nm due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses. Inset shows influence of PbF2 concentration on fluorescence decay from 4 F3/2 excited state of Nd3+ ions. All transitions of Nd3+ ions are also schematized.
lifetime (τ r = 233 s), quantum efficiency of 4 F3/2 excited state (η = 37%) and fluorescent linewidth (λ = 28 nm) were evaluated and compared for both oxide and oxyfluoride systems. The obtained data suggest that laser properties of Nd3+ ions in lead fluoroborate glasses slightly depend on PbF2 concentration. It is also in a good agreement with the results obtained by us for Nd-doped samples without PbF2 [5] and the ones obtained by Courrol et al. [6] in the case of presence PbF2 . 3.2. Influence of thermal treatment on glass properties and Nd3+ fluorescence Thermal treatment introduces a transformation from glassy material to the glass-ceramic. Narrowing of spectral lines and elongation in lifetimes of luminescent states is the spectroscopic consequence of this transformation. It is due to the structural changes in the environment surrounding optically active ions. Lead fluoroborate glasses containing Nd3+ have been analyzed as a function of thermal treatment. From DSC measurements values of glass transition temperature Tg close to 353, 332 and 310 ◦ C were obtained for the investigated oxyfluoride samples, which correspond to weak (9%), middle (36%) and high (72%) amounts of PbF2 in chemical composition. Selected Nd-doped samples were thermally treated during different conditions (temperatures and times) above Tg , at 375, 400 and 425 ◦ C, for 5, 10 and 15 h, respectively. In all cases, value of 4F 3+ 3/2 fluorescent lifetime for Nd ions in glass-ceramics was the same in comparison to precursor glass. It suggests that Nd3+ ions rather are not incorporated into crystalline phase, but they are situated in the oxide glassy matrix. This phenomenon is probably connected with chemical and structural nature of the investigated host matrices. It can be that borate units bond Nd3+ ions and block their movement to the crystalline phase. Additionally, the phonon energy of the host due to stretching vibrations of BO3 units (hν = 1300 cm−1 ) is relatively higher than other ones. Fluoride nanocrystals including Nd3+ ions are difficult to generate in transparent oxyfluoride glass-ceramics based on B2 O3 –PbF2 due to their relatively high phonon energies, corresponding to the B–O stretching vibrations. It was evidently found that the rare earth ions are preferentially incorporated into crystalline phases with small phonon energies. Thus, nanocrystalline structures can be obtained after a thermally controlled growth. However, it is possible to obtain transparent glass-ceramic materials based on B2 O3 –PbF2 . Transparent oxyfluoride glass-ceramics containing Nd3+ ions were successfully prepared, which have been evidenced by X-ray diffraction analysis. Fig. 2 presents X-ray diffraction patterns of glass and glass-ceramic obtained after thermal treatment at 400 ◦ C for 15 h. Several narrowed and relatively intense diffraction peaks were obtained after thermal treatment, which correspond to orthorhombic PbF2 phase (PDF2 card no.: P411086) with the following lattice parameters: ˚ a0 = 6.44, b0 = 3.90, c0 = 7.65 (in A). From literature it is known that lead fluoride exists in two different modifications: orthorhombic (contunite-type, ␣-PbF2 ) and cubic (fluorite-type, -PbF2 ). The ␣-PbF2 phase can be transferred irreversibly to -PbF2 phase under high-pressure
J. Pisarska et al. / Journal of Alloys and Compounds 451 (2008) 223–225
225
registered. The 4 F3/2 fluorescence lifetime of Nd3+ ions is independent on PbF2 concentration. Relatively large emission cross-section and quantum efficiency of 4 F3/2 excited state together with quite intense and long-lived NIR fluorescence are promising for laser applications. (ii) The orthorhombic PbF2 phase has been identified for Nd3+ doped transparent oxyfluoride glass-ceramics obtained after thermal treatment. However, Nd3+ ions rather are not incorporated into crystalline phase, because the 4 F3/2 fluorescence lifetime is not changed in comparison to precursor glass. Acknowledgement The work was partially supported by research project N N507 3617 33. References Fig. 2. X-ray diffraction patterns recorded for Nd3+ doped glass and transparent glass-ceramic obtained after thermal treatment at 400 ◦ C for 15 h.
and/or high-temperature conditions [9]. The  to ␣ back transformation induced by pressure or temperature is also observed. In our case, the orthorhombic PbF2 phase exists in Nd3+ -doped transparent oxyfluoride lead borate glass-ceramic materials in opposite to (i) Tm3+ ions in oxyfluoride lead germanate glass-ceramics, where cubic -PbF2 phase was identified [10,11] and (ii) Er3+ ions in multicomponent InF3 -based systems, where at least two or more crystalline phases are formed during thermal treatment [12]. 4. Conclusions Neodymium-doped oxyfluoroborate glasses have been investigated as a function of PbF2 concentration and thermal treatment. The results carried out for Nd3+ ions in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 –NdF3 oxyfluoride glass system lead to the following conclusions: (i) Fluorescence at 1.06 m due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses has been
[1] M. Abril, J. Mendez-Ramos, I.R. Martin, U.R. Rodriguez-Mendoza, V. Lavin, A. Delgado Torres, V.D. Rodriguez, P. Nunez, A.D. Lozano-Gorrin, J. Appl. Phys. 95 (2004) 5271. [2] J. Mendez-Ramos, M. Abril, I.R. Martin, U.R. Rodriguez-Mendoza, V. Lavin, V.D. Rodriguez, P. Nunez, A.D. Lozano-Gorrin, J. Appl. Phys. 99 (2006) 113510. [3] V. Lavin, I. Iparraguirre, J. Azkargorta, A. Mendioroz, J. Gonzalez-Platas, R. Balda, J. Fernandez, Opt. Mater. 25 (2004) 201. [4] D. Chen, Y. Wang, Y. Yu, Z. Hu, Mater. Sci. Eng. B 123 (2005) 1. [5] J. Pisarska, W.A. Pisarski, G. Dominiak-Dzik, W. Ryba-Romanowski, J. Mol. Struct. 792–793 (2006) 201. [6] L.C. Courrol, L.R.P. Kassab, V.D.D. Cacho, S.H. Tatumi, N.U. Wetter, J. Luminesc. 102–103 (2003) 101. [7] L.C. Courrol, B.L.S. de Lima, L.R.P. Kassab, V.D.D. Cacho, S.H. Tatumi, L. Gomes, N.U. Wetter, J. Non-Cryst. Solids 348 (2004) 98. [8] W.A. Pisarski, J. Pisarska, G. Dominiak-Dzik, Proceedings of the 17th International Conference on Photonics in Europe. World of Photonics Congress 2005. European Conference on Lasers and Electro-Optics CLEO/EUROPE—EQEC 2005, Munich, Germany, 2005. [9] S.N. Achary, A.K. Tyagi, P. Balog, J. K¨ohler, J. Alloys Compd. 417 (2006) 250. [10] W. Ryba-Romanowski, G. Dominiak-Dzik, P. Solarz, B. Klimesz, M. ˙ Zelechower, J. Non-Cryst. Solids 345–346 (2004) 391. ˙ [11] B. Klimesz, G. Dominiak-Dzik, P. Solarz, M. Zelechower, W. RybaRomanowski, J. Alloys Compd. 382 (2004) 292. [12] W.A. Pisarski, J. Pisarska, T. Goryczka, G. Dominiak-Dzik, W. RybaRomanowski, J. Alloys Compd. 398 (2005) 272.
Nd-doped oxyfluoroborate glasses and glass-ceramics for NIR laser applications J. Pisarska a,∗ , W. Ryba-Romanowski b , G. Dominiak-Dzik b , T. Goryczka c , W.A. Pisarski c a
Silesian University of Technology, Department of Materials Science, Krasi´nskiego 8, 40-019 Katowice, Poland b Institute of Low Temperature and Structure Research, Wrocław, Poland c University of Silesia, Institute of Materials Science, Katowice, Poland Available online 18 April 2007
Abstract Fluorescence at 1.06 m due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 glass system has been registered and some laser parameters for Nd3+ ions have been evaluated. The Nd-doped oxyfluoroborate glasses have been investigated as a function of PbF2 concentration and thermal treatment. The fluorescence decays from 4 F3/2 excited state of Nd3+ ions are independent on PbF2 concentration. The orthorhombic PbF2 phase has been identified for Nd-doped transparent glass-ceramics obtained after thermal treatment. © 2007 Elsevier B.V. All rights reserved. Keywords: Oxyfluoroborate glass; Glass-ceramics; Neodymium ions; Luminescence
1. Introduction Neodymium is one of the most widely studied luminescent ions emitting light especially for laser devices using the 4 F –4 I 3/2 11/2 transition at 1.06 m. Several works have been devoted to study Nd-doped optical glasses and crystals, which have attracted much attention in the design of near-infrared solidstate lasers. However, only a few works report on laser properties of Nd3+ ions in transparent oxyfluoride glass-ceramics, because Nd3+ ions do not exist in important amounts into crystalline phase. In this optical system, rare earth ions usually are incorporated in fluoride nano- or micro-crystals embedded into glassy oxide matrix. Moreover, some results obtained for transparent oxyfluoride glass-ceramics indicate that Nd3+ ions are more difficult to be incorporated into crystalline phase than other rare earth ions like Er3+ or Tm3+ . Optical properties [1] and upconversion luminescence [2] of Nd3+ in oxyfluoride glasses and transparent glass-ceramics have been reported, which were obtained by different preparation methods. Controlled crystallization (devitrification) and fluorescence properties of Nd3+ ions due to main 4 F3/2 –4 I11/2 laser transition have been examined for transparent oxyfluoride glass-ceramics containing -PbF2 [3] or CaF2 [4] phases. ∗
Corresponding author. E-mail address: [email protected] (J. Pisarska).
0925-8388/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2007.04.167
In our previous work, the Judd–Ofelt analysis and spectroscopic properties of Nd3+ ions in B2 O3 –PbO–Al2 O3 –WO3 glass systems were studied [5]. Presented work is concerned with fluorescence due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses and glass-ceramics. Optical properties [6] and up-conversion losses [7] in Nd3+ doped lead fluoroborate glasses have been examined in detail by Courrol et al. However, no information is available on Nd-doped lead fluoroborate glasses, in which PbO is partially or totally replaced by PbF2 , or during controlled crystallization. It is interesting to see how PbF2 concentration and thermal treatment influence on glass properties and Nd3+ fluorescence in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 –NdF3 system. 2. Experimental techniques Glasses in 18B2 O3 –xPbF2 –(72 − x)PbO–6Al2 O3 –3WO3 –1NdF3 (in wt%) systems (where x = 9, 18, 36, 54, 72) were prepared. Anhydrous oxides and lead fluoride (99.99% purity, Aldrich) were used as starting materials. Homogeneous mixture was heated in a protective atmosphere of dried argon. Glasses were melted at 850 ◦ C in Pt crucibles, then poured into preheated copper moulds and annealed below the glass transition temperature. After this procedure, the samples were slowly cooled to the room temperature. Transparent glassy plates were obtained in thickness of about 2 mm. Selected transparent oxyfluoride glass-ceramics were obtained by thermal treatment of the precursor glasses at their corresponding crystallization temperatures, determined by Perkin Elmer differential scanning calorimeter (DSC). The X-ray diffraction was used to verify the devitrification of the glasses. The XRD patterns were carried out using INEL diffractometer with Cu K␣ radiation in 2θ
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J. Pisarska et al. / Journal of Alloys and Compounds 451 (2008) 223–225
ranges 0–120◦ . The diffractometer is equipped with curved position sensitive detector CPS 120 which allows for data collection in 2θ range 0–120◦ . Luminescence was recorded with a Continuum Model Surelite I optical parametric oscillator pumped by a third harmonic of a Nd:YAG laser. Luminescence was dispersed by a 1 m double grating monochromator and detected with a photomultiplier with S-20 spectral response. Luminescence spectra were recorded using a Stanford SRS 250 boxcar integrator controlled by a computer. Luminescence decay curves were recorded and stored by a Tektronix TDS 3052 oscilloscope. All measurements were carried out at room temperature.
3. Results and discussion 3.1. Influence of PbF2 concentration on glass properties and Nd3+ fluorescence Nd3+
Fluorescence properties of ions in lead fluoroborate glasses have been investigated, where PbO was partially or totally replaced by PbF2 . Three emission bands at 904, 1061 and 1335 nm were registered, which can be assigned to 4 F3/2 –4 I9/2 , 4 F –4 I 4 4 3+ ions, respec3/2 11/2 and F3/2 – I13/2 transitions of Nd tively. One of them, fluorescent band at 1061 nm due to main 4 F –4 I 3+ ions in lead fluoroborate 3/2 11/2 laser transition of Nd glasses is presented in Fig. 1. Inset shows influence of PbF2 concentration on fluorescence decay from 4 F3/2 excited state of Nd3+ ions. All transitions from 4 F3/2 state of Nd3+ ions are also schematized. Any significant changes in values of 4 F3/2 fluorescence lifetime have been observed with replacement of PbO by PbF2 . Quite different situation takes place for NIR luminescence at 1.53 m due to main 4 I13/2 –4 I15/2 laser transition of Er3+ ions in lead fluoroborate glasses, where the 4 I13/2 lifetime significantly increases with increasing PbF2 content [8]. In contrast to Er3+ ions, the 4 F3/2 measured lifetime of Nd3+ ions is close to about 86 s and its value is independent on PbF2 concentration in lead fluoroborate glasses. Additionally, some laser parameters like emission cross-section (σ em = 3.58 × 10−20 cm2 ), radiative
Fig. 1. Fluorescence at 1061 nm due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses. Inset shows influence of PbF2 concentration on fluorescence decay from 4 F3/2 excited state of Nd3+ ions. All transitions of Nd3+ ions are also schematized.
lifetime (τ r = 233 s), quantum efficiency of 4 F3/2 excited state (η = 37%) and fluorescent linewidth (λ = 28 nm) were evaluated and compared for both oxide and oxyfluoride systems. The obtained data suggest that laser properties of Nd3+ ions in lead fluoroborate glasses slightly depend on PbF2 concentration. It is also in a good agreement with the results obtained by us for Nd-doped samples without PbF2 [5] and the ones obtained by Courrol et al. [6] in the case of presence PbF2 . 3.2. Influence of thermal treatment on glass properties and Nd3+ fluorescence Thermal treatment introduces a transformation from glassy material to the glass-ceramic. Narrowing of spectral lines and elongation in lifetimes of luminescent states is the spectroscopic consequence of this transformation. It is due to the structural changes in the environment surrounding optically active ions. Lead fluoroborate glasses containing Nd3+ have been analyzed as a function of thermal treatment. From DSC measurements values of glass transition temperature Tg close to 353, 332 and 310 ◦ C were obtained for the investigated oxyfluoride samples, which correspond to weak (9%), middle (36%) and high (72%) amounts of PbF2 in chemical composition. Selected Nd-doped samples were thermally treated during different conditions (temperatures and times) above Tg , at 375, 400 and 425 ◦ C, for 5, 10 and 15 h, respectively. In all cases, value of 4F 3+ 3/2 fluorescent lifetime for Nd ions in glass-ceramics was the same in comparison to precursor glass. It suggests that Nd3+ ions rather are not incorporated into crystalline phase, but they are situated in the oxide glassy matrix. This phenomenon is probably connected with chemical and structural nature of the investigated host matrices. It can be that borate units bond Nd3+ ions and block their movement to the crystalline phase. Additionally, the phonon energy of the host due to stretching vibrations of BO3 units (hν = 1300 cm−1 ) is relatively higher than other ones. Fluoride nanocrystals including Nd3+ ions are difficult to generate in transparent oxyfluoride glass-ceramics based on B2 O3 –PbF2 due to their relatively high phonon energies, corresponding to the B–O stretching vibrations. It was evidently found that the rare earth ions are preferentially incorporated into crystalline phases with small phonon energies. Thus, nanocrystalline structures can be obtained after a thermally controlled growth. However, it is possible to obtain transparent glass-ceramic materials based on B2 O3 –PbF2 . Transparent oxyfluoride glass-ceramics containing Nd3+ ions were successfully prepared, which have been evidenced by X-ray diffraction analysis. Fig. 2 presents X-ray diffraction patterns of glass and glass-ceramic obtained after thermal treatment at 400 ◦ C for 15 h. Several narrowed and relatively intense diffraction peaks were obtained after thermal treatment, which correspond to orthorhombic PbF2 phase (PDF2 card no.: P411086) with the following lattice parameters: ˚ a0 = 6.44, b0 = 3.90, c0 = 7.65 (in A). From literature it is known that lead fluoride exists in two different modifications: orthorhombic (contunite-type, ␣-PbF2 ) and cubic (fluorite-type, -PbF2 ). The ␣-PbF2 phase can be transferred irreversibly to -PbF2 phase under high-pressure
J. Pisarska et al. / Journal of Alloys and Compounds 451 (2008) 223–225
225
registered. The 4 F3/2 fluorescence lifetime of Nd3+ ions is independent on PbF2 concentration. Relatively large emission cross-section and quantum efficiency of 4 F3/2 excited state together with quite intense and long-lived NIR fluorescence are promising for laser applications. (ii) The orthorhombic PbF2 phase has been identified for Nd3+ doped transparent oxyfluoride glass-ceramics obtained after thermal treatment. However, Nd3+ ions rather are not incorporated into crystalline phase, because the 4 F3/2 fluorescence lifetime is not changed in comparison to precursor glass. Acknowledgement The work was partially supported by research project N N507 3617 33. References Fig. 2. X-ray diffraction patterns recorded for Nd3+ doped glass and transparent glass-ceramic obtained after thermal treatment at 400 ◦ C for 15 h.
and/or high-temperature conditions [9]. The  to ␣ back transformation induced by pressure or temperature is also observed. In our case, the orthorhombic PbF2 phase exists in Nd3+ -doped transparent oxyfluoride lead borate glass-ceramic materials in opposite to (i) Tm3+ ions in oxyfluoride lead germanate glass-ceramics, where cubic -PbF2 phase was identified [10,11] and (ii) Er3+ ions in multicomponent InF3 -based systems, where at least two or more crystalline phases are formed during thermal treatment [12]. 4. Conclusions Neodymium-doped oxyfluoroborate glasses have been investigated as a function of PbF2 concentration and thermal treatment. The results carried out for Nd3+ ions in multicomponent B2 O3 –PbF2 –PbO–Al2 O3 –WO3 –NdF3 oxyfluoride glass system lead to the following conclusions: (i) Fluorescence at 1.06 m due to main 4 F3/2 –4 I11/2 laser transition of Nd3+ ions in lead fluoroborate glasses has been
[1] M. Abril, J. Mendez-Ramos, I.R. Martin, U.R. Rodriguez-Mendoza, V. Lavin, A. Delgado Torres, V.D. Rodriguez, P. Nunez, A.D. Lozano-Gorrin, J. Appl. Phys. 95 (2004) 5271. [2] J. Mendez-Ramos, M. Abril, I.R. Martin, U.R. Rodriguez-Mendoza, V. Lavin, V.D. Rodriguez, P. Nunez, A.D. Lozano-Gorrin, J. Appl. Phys. 99 (2006) 113510. [3] V. Lavin, I. Iparraguirre, J. Azkargorta, A. Mendioroz, J. Gonzalez-Platas, R. Balda, J. Fernandez, Opt. Mater. 25 (2004) 201. [4] D. Chen, Y. Wang, Y. Yu, Z. Hu, Mater. Sci. Eng. B 123 (2005) 1. [5] J. Pisarska, W.A. Pisarski, G. Dominiak-Dzik, W. Ryba-Romanowski, J. Mol. Struct. 792–793 (2006) 201. [6] L.C. Courrol, L.R.P. Kassab, V.D.D. Cacho, S.H. Tatumi, N.U. Wetter, J. Luminesc. 102–103 (2003) 101. [7] L.C. Courrol, B.L.S. de Lima, L.R.P. Kassab, V.D.D. Cacho, S.H. Tatumi, L. Gomes, N.U. Wetter, J. Non-Cryst. Solids 348 (2004) 98. [8] W.A. Pisarski, J. Pisarska, G. Dominiak-Dzik, Proceedings of the 17th International Conference on Photonics in Europe. World of Photonics Congress 2005. European Conference on Lasers and Electro-Optics CLEO/EUROPE—EQEC 2005, Munich, Germany, 2005. [9] S.N. Achary, A.K. Tyagi, P. Balog, J. K¨ohler, J. Alloys Compd. 417 (2006) 250. [10] W. Ryba-Romanowski, G. Dominiak-Dzik, P. Solarz, B. Klimesz, M. ˙ Zelechower, J. Non-Cryst. Solids 345–346 (2004) 391. ˙ [11] B. Klimesz, G. Dominiak-Dzik, P. Solarz, M. Zelechower, W. RybaRomanowski, J. Alloys Compd. 382 (2004) 292. [12] W.A. Pisarski, J. Pisarska, T. Goryczka, G. Dominiak-Dzik, W. RybaRomanowski, J. Alloys Compd. 398 (2005) 272.