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Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: l -Valine hydrochloride
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Spectrochimica Acta Part A 69 (2008) 1283–1286
Short communication
Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: l-Valine hydrochloride K. Kirubavathi a , K. Selvaraju a , R. Valluvan a , N. Vijayan b , S. Kumararaman c,∗ a
Department of Physics, Thanthai Hans Roever College, Perambalur 621212, India b Materials Characterization Division, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012, India c Department of Physics, Nehru Memorial College, Puthanampatti 621007, India
Received 23 April 2007; received in revised form 14 July 2007; accepted 24 July 2007
Abstract Single crystals of a new semiorganic nonlinear optical (NLO) material, l-valine hydrochloride (LVHCl), having dimensions up to 20 mm × 6 mm × 4 mm have been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to the monoclinic system. The functional groups presented in the crystal were confirmed by Fourier transform infrared (FTIR) technique. Optical transmission spectrum shows very low absorption in the entire visible region. Differential thermal and thermogravimetric analyses confirmed that the crystal is stable up to 211 ◦ C. The powder second harmonic generation (SHG) efficiency of LVHCl is 1.7 times efficient as potassium dihydrogen phosphate (KDP). © 2007 Elsevier B.V. All rights reserved. Keywords: l-Valine hydrochloride; Single crystal X-ray diffraction; Infrared spectrum; Optical transmission spectrum; Second harmonic generation
1. Introduction The second order nonlinear optical materials have recently attracted much attention because of their potential applications in emerging optoelectronic technologies [1,2]. Materials with large second order optical nonlinearities find wide applications in the area of laser technology, laser communication and data storage technology [3,4]. The inorganic materials are widely used in these applications because of their high melting point, high mechanical strength and high degree of chemical inertness. The optical nonlinearity of these materials is poor. Organic compounds are often formed by weak Van der walls and hydrogen bonds and posses a high degree of delocalization. Hence, they are optically more nonlinear than inorganic materials. A major drawback of crystalline organic NLO materials is the difficulty in growing large, optical-quality single crystals; also, the often-
∗
Corresponding author. Tel.: +91 4327 2234227; fax: +91 4328 276344. E-mail addresses: [email protected], [email protected] (S. Kumararaman). 1386-1425/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.saa.2007.07.042
fragile nature of these crystals makes them difficult to process. In order to overcome the above said drawbacks, a new class of materials has come to be known as semiorganics. In the class of semiorganic materials, the high efficiency optical quality organic NLO materials to form the compounds in which a polarizable organic molecule is stochiometrically bonded to an inorganic host. Amino acids and their complexes belong to a family of organic materials that have applications in NLO [5–8]. Amino acids are interesting materials for NLO applications as they contain a proton donor carboxyl acid (COO) group and the proton acceptor amine (NH2 ) group with them. l-Arginine, l-arginine phosphate, l-threonine, l-threonine acetate, l-histidine, lhisditine hydrochloride are some of the examples which proved their applications in the field of NLO [9–12]. In the present work, a systematic investigation has been carried out on the growth of l-valine Hydrochloride for the first time and the grown crystals have been subjected to single crystal X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, optical transmission, thermal, second harmonic generation (SHG) efficiency studies.
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2. Experimental 2.1. Synthesis The starting material was synthesized by taking l-Valine (Loba Chemie-AR grade) and Hydrochloric acid (Merck) in a 1:1 stoichiometric ratio. The required amount of starting materials for the synthesis of l-valine hydrochloride (LVHCl) salt was calculated according to the following reaction: C5 H11 NO2 + HCl → C5 H12 NO2 Cl The calculated amount of hydrochloric acid was first dissolved in deionized water. l-Valine was then added to the solution slowly by stirring. The prepared solution was allowed to dry at room temperature and the salts were obtained by slow evaporation technique. The purity of the synthesized salt was further improved by successive recrystallization process. 2.2. Solubility In solution growth techniques, the size of a crystal depends on the amount of the material available in the solution which in turn is decided by the solubility of the material in the solvent. The solubility of LVHCl in deionized water was determined as a function of temperature in the temperature range of 30–50 ◦ C. The beaker containing the solution was maintained at a constant temperature and continuously stirred. The amount of LVHCl required to saturate at this temperature was estimated and this process repeated for various temperatures. On reaching saturation, the equilibrium concentration of the solute was determined by gravimetric method. The variation of solubility with temperature is shown in Fig. 1.
Fig. 2. Solution grown LVHCl single crystal.
3. Characterization The single crystal X-ray diffraction analysis of LVHCl crystal was carried out using ENRAF NONIUS CAD4 X-ray diffractometer and its lattice parameters were determined. Fourier transform infrared spectrum was recorded by the KBr pellet technique using a BRUKER 66 V FTIR spectrometer to confirm the vibrational structure of the crystalline compound with scanning range of wavenumber 400–4000 cm−1 . UV–vis spectrum was recorded in the range of 200–2000 nm using VARIAN CARY 5E spectrometer. Thermal behavior of the grown sample was studied by using STA 1500 thermal analyzer. The NLO property of LVHCl was tested by Kurtz powder SHG test using an Nd:YAG laser (1064 nm). 4. Results and discussion 4.1. Single crystal X-ray diffraction studies
2.3. Growth of LVHCl The saturated solution of LVHCl was prepared at room temperature from the recrystallized salt. The solution was then filtered twice to remove the suspended impurities and allowed to crystalline by the slow evaporation technique at room temperature. A good transparent crystal of size 20 mm × 6 mm × 4 mm harvested in a growth period of 30 days is shown in Fig. 2.
The single crystal X-ray diffraction has been carried out using Enraf Nonius-CAD4 diffractometer. From the measurements we found that the grown specimen of LVHCl belongs to monoclinic system having the space group P21 . The determined lattice dimensions are given in Table 1. It is in good agreement with the reported literature values. 4.2. Fourier transform infrared studies The infrared spectrum of the grown crystal has been taken in the range of 400–4000 cm−1 . The sample is made as a pellet by Table 1 Lattice parameter values of LVHCl
Fig. 1. Solubility diagram of LVHCl.
Lattice parameters
Present work
Reported work [13]
˚ a (A) ˚ b (A) ˚ c (A) β ˚ 3) Volume (A System Space group
10.23 6.97 5.49 101.5 383.59 Monoclinic –
10.38 7.08 5.46 91.30 400.8 Monoclinic P21
K. Kirubavathi et al. / Spectrochimica Acta Part A 69 (2008) 1283–1286
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hydrochloride salt of l-valine [16]. This justifies the protonation of carbonyl group in LVHCL. The absorptions of LVHCL has been compared with those of the parent compound (l-valine) in Table 2. The shifts in the positions of the characteristic peaks confirm the formation of the new compound. 4.3. Optical transmission studies Fig. 4 shows the optical transmission spectrum of LVHCl single crystal. From the spectrum, it is evident that the LVHCl crystal has a very low UV cutoff wavelength of 295 nm, along with a large transmission window in the entire visible region. Hence, it can be utilized for SHG from a laser operating at 1064 nm or other optical application in the blue region. 4.4. Thermal studies Fig. 3. FTIR spectrum of LVHCl crystal.
using KBr. The Fourier transform infrared (FTIR) spectrum of LVHCL is shown in Fig. 3. The spectrum shows the presence of all the functional groups in LVHCL crystal and summarized in Table 2. A broad, strong absorption in the 2900–3300 cm−1 range, including the absorption at 3082 cm−1 correspond to the stretching band of the NH3 + ion of the amino acid. This region results from superimposed O–H and NH3 + stretching bands. Absorption in this region is also characterized by multiple fine structures on the lower wavenumber side of the band and weak absorptions due to COO− ions. Also, prominent is the relatively strong symmetrical NH3 + bending band around 1519 cm−1 [14]. A strong band arising from C–COO− stretching is observed at 1216 cm−1 [15]. Further a strong carbonyl absorptions at 1743 cm−1 confirms the COOH and COO− groups of the compound. Appearance of this band confirms the formation of Table 2 FTIR spectral band assignments of LVHCl Wavenumber (cm−1 )
Assignments
l-Valine [17]
LVHCL
543 490 720 892 1032
582 486 714 854 1068
COO− rocking NH3 + torsion COO− in-plane deformation CH2 rocking C–N stretching
1147
1151 1216
ND3 + symmetric deformation C COO− stretching
1278 1402 1465 1512
1285 1414 1475 1519
CH3 rocking COO− symmetric stretching CH3 asymmetric stretching NH3 + symmetric deformation
1621
1629 1743
NH3 + degenerative deformation COO− stretching
2110 2600
1991 2574
O H O stretching N H stretching
3053
3082 3412
N H stretching C O stretching
To find the thermal characteristics of LVHCl, differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were carried out simultaneously in a thermal analyzer (STA 1500). The sample was heated at a rate of 10 ◦ C/min in protected nitrogen gas flow. 1.25 mg of the sample was taken to carry out the experiment. Fig. 5 shows the thermograms illustrating simultaneously recorded TGA and DTA. From DT curve, it is observed that the material undergoes an irreversible endothermic transition at about 211 ◦ C where the decomposition starts. The material is fully decomposed at 260 ◦ C. The weight loss curve is very sharp and it starts at 211 ◦ C and ends at 277 ◦ C. This weight loss is due to the liberation of volatile substances. The sharpness of the endothermic peak shows good degree of crystallinity of the grown ingot. The peak at 277 ◦ C indicates a phase change from liquid to vapor state as evidence from the loss of weight in the TG curve. 4.5. Second harmonic generation The second harmonic generation (SHG) test on the LVHCl crystal was performed by Kurtz powder SHG method [18]. The powdered sample of LVHCl crystal was illuminated using the fundamental beam of 1064 nm from Q-switched Nd:YAG laser. Pulse energy 4 mJ/pulse and pulse width of 10 ns and repetition rate of 10 Hz were used. The second harmonic signal generated in the crystalline sample was confirmed from the emission of
Fig. 4. Optical transmission spectrum of LVHCl.
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Fig. 5. TG/DTA curve of LVHCl crystal.
green radiation of wavelength 532 nm collected a monochromator after separating the 1064 nm pump beam with an IR-blocking filter. A photomultiplier tube is used as detector. It is observed that the measured SHG efficiency of LVHCl crystal was 1.7 times that of potassium dihydrogen phosphate (KDP). 5. Conclusion A new nonlinear semiorganic material l-valine hydrochloride (LVHCL) was synthesized. Optical quality single crystal of LVHCl was grown by slow evaporation solution growth technique using water as solvent. The structure of the grown crystals was confirmed by single crystal XRD analysis. The presence of various functional groups present in the crystal has been confirmed by FTIR spectral analysis. Optical transmission studies show that the grown crystal were optically transparent the λcutoff occurs at 295 nm. From the thermal studies it is observed that the material is thermally stable up to 211 ◦ C. Kurtz powder SHG test confirms the frequency doubling of the grown crystal and its efficiency is higher than that of KDP. Thus LVHCl can act as a promising material for nonlinear optical applications. References [1] H.O. Mercy, L.F. Warren, M.S. Webb, C.A. Ebbers, S.P. Velsko, G.C. Kennedy, G.C. Catella, Appl. Opt. 31 (1992) 5051.
[2] X.Q. Wang, D. Xu, D.R. Yuan, Y.P. Tian, W.T. Yu, S.Y. Sun, Z.H. Yang, Q. Fang, M.K. Lu, Y.X. Yan, F.Q. Meng, S.Y. Guo, G.H. Zhang, M.H. Jiang, Met. Res. Bull. 34 (2003) 1999. [3] P.A. Angelimary, S. Dhanuskodi, Cryst. Res. Technol. 36 (2001) 1231. [4] R. Rajasekaran, P. Mohan Kumar, R. Jayavel, P. Ramasamy, J. Cryst. Growth 311 (2002) 270. [5] D. Xu, M. Jiang, Z. Tan, Acta Chem. Sin. 41 (1983) 570. [6] M. Kitazawa, R. Higuchi, M. Takahashi, App. Phys. Lett. 64 (1994) 2477. [7] L. Misogati, A.T. Varela, F.D. Nunes, V.S. Bagnato, F.E.A. Melo, J. Mendes Filho, C. Zilio, Opt. Mater. 6 (1996) 147. [8] W.S. Wang, M.D. Aggarwal, J. Choi, T. Gebre, A.D. Shields, B.G. Penn, D.O. Frazier, J. Cryst. Growth 578 (1999) 198. [9] S.B. Monaco, L.E. Davis, S.P. Velsko, F.T. Wang, D. Eimerl, A.J. Zalkin, J. Cryst. Growth 85 (1987) 252. [10] G. Ramesh Kumar, S. Gokul Raj, R. Mohan, R. Jayavel, Cryst. Growth Des. 6 (2006) 1308. [11] G. Ramesh Kumar, S. Gokul Raj, R. Mohan, R. Jayavel, J. Cryst. Growth 283 (2005) 193. [12] H.A. Petrosyan, H.A. Karapetyan, M.Yu. Antinpin, A.M. Petrosyan, J. Cryst. Growth 275 (2005) e1919. [13] R. Parthasarathy, Acta Crystallogr. 21 (1966) 422. [14] A.R. Gargaro, L.D. Barron, L. Hecht, J. Raman Spectrosc. 24 (1993) 91. [15] K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds, Wiley & Sons, New York, 1986. [16] J. Mohan, Organic Spectroscopy Principles and Applications, Narosa Publishing House, New Delhi, 2005. [17] R.S. Krishnan, V.N. Sankaranarayanan, K. Krishnan, J. Indian Inst. Sci. 55 (1973) 66. [18] S.K. Kurtz, T.T. Perry, J. Appl. Phys. 39 (1968) 3798.
Spectrochimica Acta Part A 69 (2008) 1283–1286
Short communication
Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: l-Valine hydrochloride K. Kirubavathi a , K. Selvaraju a , R. Valluvan a , N. Vijayan b , S. Kumararaman c,∗ a
Department of Physics, Thanthai Hans Roever College, Perambalur 621212, India b Materials Characterization Division, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012, India c Department of Physics, Nehru Memorial College, Puthanampatti 621007, India
Received 23 April 2007; received in revised form 14 July 2007; accepted 24 July 2007
Abstract Single crystals of a new semiorganic nonlinear optical (NLO) material, l-valine hydrochloride (LVHCl), having dimensions up to 20 mm × 6 mm × 4 mm have been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to the monoclinic system. The functional groups presented in the crystal were confirmed by Fourier transform infrared (FTIR) technique. Optical transmission spectrum shows very low absorption in the entire visible region. Differential thermal and thermogravimetric analyses confirmed that the crystal is stable up to 211 ◦ C. The powder second harmonic generation (SHG) efficiency of LVHCl is 1.7 times efficient as potassium dihydrogen phosphate (KDP). © 2007 Elsevier B.V. All rights reserved. Keywords: l-Valine hydrochloride; Single crystal X-ray diffraction; Infrared spectrum; Optical transmission spectrum; Second harmonic generation
1. Introduction The second order nonlinear optical materials have recently attracted much attention because of their potential applications in emerging optoelectronic technologies [1,2]. Materials with large second order optical nonlinearities find wide applications in the area of laser technology, laser communication and data storage technology [3,4]. The inorganic materials are widely used in these applications because of their high melting point, high mechanical strength and high degree of chemical inertness. The optical nonlinearity of these materials is poor. Organic compounds are often formed by weak Van der walls and hydrogen bonds and posses a high degree of delocalization. Hence, they are optically more nonlinear than inorganic materials. A major drawback of crystalline organic NLO materials is the difficulty in growing large, optical-quality single crystals; also, the often-
∗
Corresponding author. Tel.: +91 4327 2234227; fax: +91 4328 276344. E-mail addresses: [email protected], [email protected] (S. Kumararaman). 1386-1425/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.saa.2007.07.042
fragile nature of these crystals makes them difficult to process. In order to overcome the above said drawbacks, a new class of materials has come to be known as semiorganics. In the class of semiorganic materials, the high efficiency optical quality organic NLO materials to form the compounds in which a polarizable organic molecule is stochiometrically bonded to an inorganic host. Amino acids and their complexes belong to a family of organic materials that have applications in NLO [5–8]. Amino acids are interesting materials for NLO applications as they contain a proton donor carboxyl acid (COO) group and the proton acceptor amine (NH2 ) group with them. l-Arginine, l-arginine phosphate, l-threonine, l-threonine acetate, l-histidine, lhisditine hydrochloride are some of the examples which proved their applications in the field of NLO [9–12]. In the present work, a systematic investigation has been carried out on the growth of l-valine Hydrochloride for the first time and the grown crystals have been subjected to single crystal X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, optical transmission, thermal, second harmonic generation (SHG) efficiency studies.
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K. Kirubavathi et al. / Spectrochimica Acta Part A 69 (2008) 1283–1286
2. Experimental 2.1. Synthesis The starting material was synthesized by taking l-Valine (Loba Chemie-AR grade) and Hydrochloric acid (Merck) in a 1:1 stoichiometric ratio. The required amount of starting materials for the synthesis of l-valine hydrochloride (LVHCl) salt was calculated according to the following reaction: C5 H11 NO2 + HCl → C5 H12 NO2 Cl The calculated amount of hydrochloric acid was first dissolved in deionized water. l-Valine was then added to the solution slowly by stirring. The prepared solution was allowed to dry at room temperature and the salts were obtained by slow evaporation technique. The purity of the synthesized salt was further improved by successive recrystallization process. 2.2. Solubility In solution growth techniques, the size of a crystal depends on the amount of the material available in the solution which in turn is decided by the solubility of the material in the solvent. The solubility of LVHCl in deionized water was determined as a function of temperature in the temperature range of 30–50 ◦ C. The beaker containing the solution was maintained at a constant temperature and continuously stirred. The amount of LVHCl required to saturate at this temperature was estimated and this process repeated for various temperatures. On reaching saturation, the equilibrium concentration of the solute was determined by gravimetric method. The variation of solubility with temperature is shown in Fig. 1.
Fig. 2. Solution grown LVHCl single crystal.
3. Characterization The single crystal X-ray diffraction analysis of LVHCl crystal was carried out using ENRAF NONIUS CAD4 X-ray diffractometer and its lattice parameters were determined. Fourier transform infrared spectrum was recorded by the KBr pellet technique using a BRUKER 66 V FTIR spectrometer to confirm the vibrational structure of the crystalline compound with scanning range of wavenumber 400–4000 cm−1 . UV–vis spectrum was recorded in the range of 200–2000 nm using VARIAN CARY 5E spectrometer. Thermal behavior of the grown sample was studied by using STA 1500 thermal analyzer. The NLO property of LVHCl was tested by Kurtz powder SHG test using an Nd:YAG laser (1064 nm). 4. Results and discussion 4.1. Single crystal X-ray diffraction studies
2.3. Growth of LVHCl The saturated solution of LVHCl was prepared at room temperature from the recrystallized salt. The solution was then filtered twice to remove the suspended impurities and allowed to crystalline by the slow evaporation technique at room temperature. A good transparent crystal of size 20 mm × 6 mm × 4 mm harvested in a growth period of 30 days is shown in Fig. 2.
The single crystal X-ray diffraction has been carried out using Enraf Nonius-CAD4 diffractometer. From the measurements we found that the grown specimen of LVHCl belongs to monoclinic system having the space group P21 . The determined lattice dimensions are given in Table 1. It is in good agreement with the reported literature values. 4.2. Fourier transform infrared studies The infrared spectrum of the grown crystal has been taken in the range of 400–4000 cm−1 . The sample is made as a pellet by Table 1 Lattice parameter values of LVHCl
Fig. 1. Solubility diagram of LVHCl.
Lattice parameters
Present work
Reported work [13]
˚ a (A) ˚ b (A) ˚ c (A) β ˚ 3) Volume (A System Space group
10.23 6.97 5.49 101.5 383.59 Monoclinic –
10.38 7.08 5.46 91.30 400.8 Monoclinic P21
K. Kirubavathi et al. / Spectrochimica Acta Part A 69 (2008) 1283–1286
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hydrochloride salt of l-valine [16]. This justifies the protonation of carbonyl group in LVHCL. The absorptions of LVHCL has been compared with those of the parent compound (l-valine) in Table 2. The shifts in the positions of the characteristic peaks confirm the formation of the new compound. 4.3. Optical transmission studies Fig. 4 shows the optical transmission spectrum of LVHCl single crystal. From the spectrum, it is evident that the LVHCl crystal has a very low UV cutoff wavelength of 295 nm, along with a large transmission window in the entire visible region. Hence, it can be utilized for SHG from a laser operating at 1064 nm or other optical application in the blue region. 4.4. Thermal studies Fig. 3. FTIR spectrum of LVHCl crystal.
using KBr. The Fourier transform infrared (FTIR) spectrum of LVHCL is shown in Fig. 3. The spectrum shows the presence of all the functional groups in LVHCL crystal and summarized in Table 2. A broad, strong absorption in the 2900–3300 cm−1 range, including the absorption at 3082 cm−1 correspond to the stretching band of the NH3 + ion of the amino acid. This region results from superimposed O–H and NH3 + stretching bands. Absorption in this region is also characterized by multiple fine structures on the lower wavenumber side of the band and weak absorptions due to COO− ions. Also, prominent is the relatively strong symmetrical NH3 + bending band around 1519 cm−1 [14]. A strong band arising from C–COO− stretching is observed at 1216 cm−1 [15]. Further a strong carbonyl absorptions at 1743 cm−1 confirms the COOH and COO− groups of the compound. Appearance of this band confirms the formation of Table 2 FTIR spectral band assignments of LVHCl Wavenumber (cm−1 )
Assignments
l-Valine [17]
LVHCL
543 490 720 892 1032
582 486 714 854 1068
COO− rocking NH3 + torsion COO− in-plane deformation CH2 rocking C–N stretching
1147
1151 1216
ND3 + symmetric deformation C COO− stretching
1278 1402 1465 1512
1285 1414 1475 1519
CH3 rocking COO− symmetric stretching CH3 asymmetric stretching NH3 + symmetric deformation
1621
1629 1743
NH3 + degenerative deformation COO− stretching
2110 2600
1991 2574
O H O stretching N H stretching
3053
3082 3412
N H stretching C O stretching
To find the thermal characteristics of LVHCl, differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were carried out simultaneously in a thermal analyzer (STA 1500). The sample was heated at a rate of 10 ◦ C/min in protected nitrogen gas flow. 1.25 mg of the sample was taken to carry out the experiment. Fig. 5 shows the thermograms illustrating simultaneously recorded TGA and DTA. From DT curve, it is observed that the material undergoes an irreversible endothermic transition at about 211 ◦ C where the decomposition starts. The material is fully decomposed at 260 ◦ C. The weight loss curve is very sharp and it starts at 211 ◦ C and ends at 277 ◦ C. This weight loss is due to the liberation of volatile substances. The sharpness of the endothermic peak shows good degree of crystallinity of the grown ingot. The peak at 277 ◦ C indicates a phase change from liquid to vapor state as evidence from the loss of weight in the TG curve. 4.5. Second harmonic generation The second harmonic generation (SHG) test on the LVHCl crystal was performed by Kurtz powder SHG method [18]. The powdered sample of LVHCl crystal was illuminated using the fundamental beam of 1064 nm from Q-switched Nd:YAG laser. Pulse energy 4 mJ/pulse and pulse width of 10 ns and repetition rate of 10 Hz were used. The second harmonic signal generated in the crystalline sample was confirmed from the emission of
Fig. 4. Optical transmission spectrum of LVHCl.
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Fig. 5. TG/DTA curve of LVHCl crystal.
green radiation of wavelength 532 nm collected a monochromator after separating the 1064 nm pump beam with an IR-blocking filter. A photomultiplier tube is used as detector. It is observed that the measured SHG efficiency of LVHCl crystal was 1.7 times that of potassium dihydrogen phosphate (KDP). 5. Conclusion A new nonlinear semiorganic material l-valine hydrochloride (LVHCL) was synthesized. Optical quality single crystal of LVHCl was grown by slow evaporation solution growth technique using water as solvent. The structure of the grown crystals was confirmed by single crystal XRD analysis. The presence of various functional groups present in the crystal has been confirmed by FTIR spectral analysis. Optical transmission studies show that the grown crystal were optically transparent the λcutoff occurs at 295 nm. From the thermal studies it is observed that the material is thermally stable up to 211 ◦ C. Kurtz powder SHG test confirms the frequency doubling of the grown crystal and its efficiency is higher than that of KDP. Thus LVHCl can act as a promising material for nonlinear optical applications. References [1] H.O. Mercy, L.F. Warren, M.S. Webb, C.A. Ebbers, S.P. Velsko, G.C. Kennedy, G.C. Catella, Appl. Opt. 31 (1992) 5051.
[2] X.Q. Wang, D. Xu, D.R. Yuan, Y.P. Tian, W.T. Yu, S.Y. Sun, Z.H. Yang, Q. Fang, M.K. Lu, Y.X. Yan, F.Q. Meng, S.Y. Guo, G.H. Zhang, M.H. Jiang, Met. Res. Bull. 34 (2003) 1999. [3] P.A. Angelimary, S. Dhanuskodi, Cryst. Res. Technol. 36 (2001) 1231. [4] R. Rajasekaran, P. Mohan Kumar, R. Jayavel, P. Ramasamy, J. Cryst. Growth 311 (2002) 270. [5] D. Xu, M. Jiang, Z. Tan, Acta Chem. Sin. 41 (1983) 570. [6] M. Kitazawa, R. Higuchi, M. Takahashi, App. Phys. Lett. 64 (1994) 2477. [7] L. Misogati, A.T. Varela, F.D. Nunes, V.S. Bagnato, F.E.A. Melo, J. Mendes Filho, C. Zilio, Opt. Mater. 6 (1996) 147. [8] W.S. Wang, M.D. Aggarwal, J. Choi, T. Gebre, A.D. Shields, B.G. Penn, D.O. Frazier, J. Cryst. Growth 578 (1999) 198. [9] S.B. Monaco, L.E. Davis, S.P. Velsko, F.T. Wang, D. Eimerl, A.J. Zalkin, J. Cryst. Growth 85 (1987) 252. [10] G. Ramesh Kumar, S. Gokul Raj, R. Mohan, R. Jayavel, Cryst. Growth Des. 6 (2006) 1308. [11] G. Ramesh Kumar, S. Gokul Raj, R. Mohan, R. Jayavel, J. Cryst. Growth 283 (2005) 193. [12] H.A. Petrosyan, H.A. Karapetyan, M.Yu. Antinpin, A.M. Petrosyan, J. Cryst. Growth 275 (2005) e1919. [13] R. Parthasarathy, Acta Crystallogr. 21 (1966) 422. [14] A.R. Gargaro, L.D. Barron, L. Hecht, J. Raman Spectrosc. 24 (1993) 91. [15] K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds, Wiley & Sons, New York, 1986. [16] J. Mohan, Organic Spectroscopy Principles and Applications, Narosa Publishing House, New Delhi, 2005. [17] R.S. Krishnan, V.N. Sankaranarayanan, K. Krishnan, J. Indian Inst. Sci. 55 (1973) 66. [18] S.K. Kurtz, T.T. Perry, J. Appl. Phys. 39 (1968) 3798.