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Radiation Effects and Defects in Solids 02/2013; · 0.40 Impact Factor
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CrystEngComm 01/2013; · 3.84 Impact Factor
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ABSTRACT: Good quality ADP–KDP mixed crystal (90:10) is grown by slow cooling method. The size of the grown crystal is 80×10×10 mm3. The mounted seed size was 5×10×10 mm3 and the crystal was grown along the ‘c’ axis. HRXRD studies have been done in the near and far regions of the seed crystal. The FWHM of these diffraction curves are 28 and 29 arcsec, which are almost the same. The close values of FWHM of both the specimens indicate that the quality of the crystal remains nearly the same throughout the crystal. 80% of transparency is observed from the UV–vis studies in the entire visible region. Vickers hardness studies indicate that the mixed crystal is mechanically more stable compared to the ADP. Higher piezoelectric coefficient is observed in mixed crystals. Dielectric measurements are carried out. From the laser damage threshold studies, it is observed that higher energy is required to damage the mixed crystal and it indicates that the laser stability of the mixed crystal is high
Journal of Crystal Growth 01/2013; 362:338-342. · 1.73 Impact Factor
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ABSTRACT: Zr–Fe-doped congruent lithium niobate single crystals were grown by the
Czochralski technique. The crystal structure and lattice parameter of the grown
crystals were assessed by powder X-ray diffraction and the strain developed as a
result of doping has been calculated (�1.19 � 10�3) by using the Williamson–
Hall relation. The incorporated dopant concentration along with the dopant
distribution in the specimen crystal was estimated by X-ray florescence
spectrometry. A multi-crystal X-ray diffraction analysis was carried out to
identify the crystalline perfection of the sample and revealed that the
investigated crystal does not contain any structural grain boundaries but does
contain point defects and micrometre size mosaic blocks. Birefringence
measurements were carried out using a prism coupler spectrometer and found
that the optical birefringence is 0.0822 for 532 nm and 0.705 for 1064 nm. A
thermal conductivity (�) study reveals that the doped sample has a lower � value
than the undoped equivalent.
Journal of Applied Crystallography 01/2013; 46. · 5.15 Impact Factor
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ABSTRACT: The potential organic non-linear optical single crystal of L-lysine acetate has been grown by slow evaporation solution growth technique (SEST) at room temperature. It crystallizes in the monoclinic system with space group of P2(1). The crystalline perfection of the grown single crystal has been examined by high resolution X-ray diffraction analysis (HRXRD). The functional groups of the synthesized compound have been identified by (13)C NMR, (1)H NMR and FTIR analyses. The optical absorption studies show that the crystal is transparent in the entire visible region with a cut-off wavelength of 236nm. The optical band gap is found to be 5.29eV. The steady-state PL spectra was recorded for pure L-lysine acetate crystal at room temperature. The third harmonic generation efficiency of the crystal has been evaluated by Z-scan technique and its non-linear optical coefficient has been calculated. Birefringence measurement has been carried out in order to see the optical homogeneity of the grown specimen. Its electrical properties has been assessed by dielectric measurement at different temperatures. The calculated optical band gap is 5.29eV. Its thermal parameters like thermal diffusivity (α), thermal effusivity (e), thermal conductivity (k) and heat capacity (C(p)) have been determined by photopyroelectric technique. Vickers micro hardness studies were carried out using a Vickers hardness tester equipped with a diamond square indenter. The piezoelectric measurement for L-lysine acetate has been also been carried at ambient condition.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2012; 105C:192-199. · 2.10 Impact Factor
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ABSTRACT: One of the Schiff base 4-bromo-4'dimethylamino benzylideneaniline (BDMABA) compounds was synthesized and single crystal of the material was grown by solvent evaporation method at room temperature. Molecular structure of BDMABA was confirmed by (1)H nuclear magnetic resonance and the presence of functional groups was confirmed by Fourier Transform Infrared and Fourier Transform Raman spectral analyses. Cell parameters were determined using single crystal X-ray diffraction analysis and crystalline perfection of the grown BDMABA crystal was evaluated using high-resolution X-ray diffraction analysis. Thermal analyses indicated that the material is thermally stable up to 215°C and its melting point is 161.5°C. Vickers microhardness study was carried out to estimate the mechanical hardness of BDMABA crystal which shows that the crystal belongs to the class of soft materials. Linear and nonlinear optical studies were carried out using UV-vis-NIR spectrum and open aperture Z-scan technique respectively.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2012; 104C:403-408. · 2.10 Impact Factor
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Mohd Shkir,
V Ganesh,
N Vijayan,
B Riscob,
Anoop Kumar,
Devendra Kumar Rana,
Mohd Shoeb Khan,
Mohd Hasmuddin,
M A Wahab,
R Ramesh Babu, G Bhagavannarayana
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ABSTRACT: Good quality single crystals of potassium dihydrogen orthophosphate (KDP) were grown with different doping concentration of Glycine by conventional solution technique in aqueous solution. X-ray diffraction study has been carried out in order to see the effect of dopant on the structural parameters of KDP. There is no additional phase was observed which was further confirmed by Raman spectroscopic analysis. The second harmonic generation efficiency was measured by using Kurtz powder technique. The relative second harmonic generation (SHG) efficiency of the grown crystals was found to be increased with doping concentration up to 2.5mol%. Optical transmission study also revealed the same behaviour with enhancement up to 2.5mol% concentration and later decreased but still higher than pure KDP. The mechanical strength was found to increase with increasing the doping concentration.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 11/2012; 103C:199-204. · 2.10 Impact Factor
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ABSTRACT: Ammonium Hydrogen l-tartarte (AMT), an organic nonlinear optical crystal was grown by slow evaporation method at ambient temperature. Solubility, metastable zone width and induction period of Ammonium Hydrogen l-tartarte in aqueous solution were determined. Good quality crystals were selected and characterized by Single crystal XRD, HR-XRD, FT-IR, (1)H NMR, Mass, TGA-DTA, SEM, EDAX, optical and NLO studies. Single crystal XRD analysis revealed that the crystal system belongs to orthorhombic with cell parameters a=7.65Å, b=7.85Å and c=11.07Å. High-resolution-X-ray diffraction (HR-XRD) analysis was carried out to study the crystalline perfection of the grown crystal. (1)H NMR and FTIR spectrum thus confirmed the presence of functional groups of the grown crystal. Molecular mass of AMT was measured accurately by mass spectroscopic analysis. Surface features of the grown crystal were analyzed by SEM, AFM, chemical etching and the presence of elements in the compound was identified by EDAX analysis. Thermal behavior of the grown crystal has been studied by TG/DTA analysis. The recorded UV-Vis-NIR spectrum shows excellent transmission in the region of 190-1100nm. The Vickers and Knoop's microhardness studies have been carried out on AMT crystals over a range of 10-50g. Hardness anisotropy has been observed in accordance with the orientation of the crystal. Fluorescence spectral studies were carried in the range of 280-500nm for the grown crystal. The SHG conversion efficiency and laser damage threshold were measured using an Nd: YAG laser (1064nm).
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 11/2012; 103C:388-399. · 2.10 Impact Factor
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ABSTRACT: Single crystal of an organic material, 4-chloro-4'bromobenzylidene aniline (CBBA), was synthesized and grown by slow evaporation method at room temperature. (1)H and (13)C NMR spectra were recorded to elucidate the molecular structure and functional groups of CBBA were identified using FTIR and FT Raman spectral analyses. The lattice parameters were calculated from single crystal X-ray diffraction data. Single and reasonably sharp peak observed in the high resolution X-ray diffraction curve indicates that the quality of the crystal is good. Thermal properties of CBBA were carried out using thermogravimetric, differential thermal and differential scanning calorimetric analyses and the melting point of the CBBA material is ∼123°C. The dielectric properties of CBBA crystal was studied as the function of frequency (100Hz-500kHz). The optical properties were ascertained by recording UV-vis-NIR and fluorescence spectrum. Further the mechanical properties were studied using Vickers microhardness test.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2012; 96:716-22. · 2.10 Impact Factor
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ABSTRACT: In the present study, single crystals of �-glycine possessing excellent non-linear optical properties were
successfully grown at room temperature in the presence of magnesium chloride (MgCl2) for the first
time by using the slow solvent evaporation method. The second harmonic conversion efficiency of �-
glycine crystal was determined using Kurtz powder technique with Nd:YAG laser and was found to be
6 times greater than that of the standard inorganic sample potassium dihydrogen phosphate (KDP). The
crystalline perfection of the grown crystal was analyzed using high-resolution X-ray diffraction (HRXRD)
rocking curve measurements. The grown crystal was subjected to single crystal XRD and powder XRD,
which confirmed that the crystal has hexagonal structure and belongs to space group P31. Inductively
coupled plasma optical emission spectrometry (ICP-OES) was carried out to quantify the concentration of
Mg element in the grown �-glycine single crystal. Fourier transform infrared (FTIR) spectral studies were
made to identify the functional groups. The optical band gap was likewise estimated for �-glycine crystal
using UV–vis–NIR study. The optical measurements of �-glycine crystal helped to calculate the optical
constants such as refractive index (n), the extinction coefficient (K), electric susceptibility (�c) and both
the real (∈r) and imaginary (∈i) components of the dielectric permittivity functions of photon energy,
which is essentially required to develop optoelectronic devices. Thermogravimetric analysis (TGA) and
differential thermal analysis (DTA) were used to study thermal stability and decomposition point of the
grown crystal.
Materials Chemistry and Physics 04/2012; · 2.23 Impact Factor
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ABSTRACT: Single crystals of benzophenone oxime (BPO) have been grown by slow evaporation solution growth technique from ethanol at room temperature. The single crystal X-ray diffraction study reveals that the crystal belongs to monoclinic system and cell parameters are, a=9.459 Å, b=8.383 Å, c=26.690 Å, v=2115 Å(3) and β=92.807°. The structure and the crystallinity of the materials were further confirmed by powder X-ray diffraction analysis. The various functional groups present in the molecule are confirmed by FT-IR analysis. The TG/DSC studies reveal the purity of the material and the crystals are transparent in the entire visible region having a lower optical cut-off at ~300 nm. The crystalline perfection was evaluated by high-resolution X-ray diffraction (HRXRD). The crystal is further characterized by Kurtz powder technique, dielectric studies and microhardness analysis.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2012; 92:207-11. · 2.10 Impact Factor
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ABSTRACT: Single crystals of organic nonlinear material urea thiosemicarbazone monohydrate (UTM) have been grown by slow evaporation method. The grown crystals were characterized by single crystal X-ray diffraction analysis reveals that sample crystallized in triclinic system with noncentrosymmetric space group P1. Powder XRD pattern confirmed that grown crystal posses highly crystalline nature. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by (1)H NMR spectrum. Material confirmation of title compound has been performed by using mass spectroscopic analysis. Elemental composition of grown crystal was confirmed by energy-dispersive spectrometry (EDS). To study the crystalline perfection of the grown crystals, high-resolution X-ray diffraction (HR-XRD) study was carried out. Thermogravimetric and differential thermal analyses were employed to understand the thermal and physio-chemical stability of the synthesized compound. UV-Vis-NIR spectrum revealed the transmission properties of the crystal specimen. Relative SHG efficiency is measured by Kurtz and Perry method and found to about 0.89 times that of standard potassium dihydrogen phosphate (KDP) crystals.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2012; 91:345-51. · 2.10 Impact Factor
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ABSTRACT: Organic scintillation materials are very much useful in the area of nuclear experiments, medical diag-nostics and therapy. In the present investigation, we have systematically analyzed the vertical Bridgman grown organic scintillation material of trans-stilbene which is annealed at different annealing tempera-tures. Remarkable changes have been observed on its structural and optical properties. High resolution X-ray diffraction (HRXRD) analysis shows noticeable difference for the annealed specimen than the as-grown crystal. The observed results exposed that the crystalline quality was drastically improved by the elimination of defects or low angle boundaries by post growth annealing technique. Its optical behavior has been examined by photoluminescence, Raman and IR analyses. Vickers microhardness measurement has been carried out and found that hardness values increases for the annealed trans-stilbene single crystals.
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ABSTRACT: In the recent past, nonlinear optical materials are getting attention in the field fibre optic communica-tion and optical signal processing. In the present study, the title compound was successfully synthesized by conventional chemical reaction and then the single crystal was grown by slow evaporation solution growth technique. l-Arginine acetate (LAA) is semi organic non linear optical single crystal and crystal-lizes in noncentrosymmetric space group. The grown good quality single crystals have been analyzed by different characterization analyses such as powder X-ray diffraction, high resolution X-ray diffraction (HRXRD), Raman spectroscopy, photoluminescence, SEM, micro-hardness, thermal and birefringence analyses.
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ABSTRACT: a b s t r a c t Single crystals of L-histidine nitrate (LHN), a recently investigated nonlinear optical material, were grown by conventional solution technique. Crystal structure and vibrational modes of the grown crystals were confirmed by powder X-ray diffractometry and FT-Raman spectrometry, respectively. Crystalline perfection of the grown crystals was evaluated by employing an in-house developed high-resolution X-ray diffractometer (HRXRD) and it was found that the grown crystals were free from structural grain boundaries and the perfection was reasonably good. However, HRXRD could reveal the fact that the crystals contain predominantly the interstitial point defects. The birefringence was measured over a range of wavelength between 5480 and 563 A and it was found that its value is nearly constant and 10 times higher than that of KDP. The optical band gap was found to be $ 3.73 eV. The photoluminescence excitation and emission spectra for single crystals were recorded. The SHG efficiencies of LHN samples of different particle sizes were measured by the Kurtz and Perry technique and they removed the ambiguity in the values reported differently in the literature. Dielectric properties were studied as a function of temperature over a wide range of frequency. The optical and dielectric studies along with the crystalline perfection reveal that the LHN crystal could be a good candidate for nonlinear optical devices.
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ABSTRACT: Thiosemicarbazide hydrochloride (TSCHCL) was synthesized by mixing thiosemicarbazide and hydrochloride in 1:1 molar ratio in double distilled water. Single crystals of TSCHCL were grown by slow evaporation at room temperature and were characterized by single crystal X-ray diffraction study to determine the molecular structure and by FT-IR, (1)H and (13)C NMR spectral analyses to confirm the synthesized compound. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. The transmission spectrum of TSCHCL showed that the crystal is transparent in the wavelength range 380-1100 nm. High resolution X-ray diffractometry (HRXRD) was employed to evaluate the perfection of the grown crystal. Mechanical properties of the grown crystal were studied using Vickers microhardness test. Second harmonic generation efficiency of the powdered TSCHCL was tested using Nd:YAG laser and is ∼1.5 times that of potassium dihydrogen orthophosphate.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2011; 82(1):102-7. · 2.10 Impact Factor
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ABSTRACT: The organic material 4-chloro-4'-chlorobenzylidene aniline (CCBA) was synthesized and confirmed by NMR and FTIR spectral analyses. CCBA crystal was grown from chloroform by slow evaporation at room temperature and the single crystal cell parameters were determined by single crystal X-ray diffraction method. The perfection of the grown crystal was analyzed by high resolution X-ray diffraction rocking curve analysis. Fluorescence spectrum indicated violet emission at 428 nm. The range of optical absorbance was ascertained by recording UV-vis-NIR spectrum. Load dependant microhardness measurements on this crystal revealed the mechanical behavior of the material. Stiffness constant, Meyer index and yield strength of CCBA crystal were calculated. Dielectric studies were carried out to estimate the dielectric parameters of the grown crystal in the frequency range from 100 Hz to 100 kHz. The thermal behavior of CCBA was investigated using differential scanning calorimetry (DSC) and no phase transition was identified in the temperature region 30-100°C. Further, the CCBA crystal was subjected to open aperture Z-scan studies in order to investigate the third order nonlinear optical (NLO) properties of CCBA crystal.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2011; 82(1):91-6. · 2.10 Impact Factor
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ABSTRACT: Single crystals of γ-glycine, an organic nonlinear optical material have been synthesized in the presence of potassium fluoride (KF) by slow evaporation technique at ambient temperature. The size of the grown crystal is up to the dimension of 12 mm×10 mm×8 mm. The γ-phase was confirmed by single crystal X-ray diffraction, powder XRD and the FTIR analysis. Optical absorption spectrum reveals that the grown crystal has good optical transparency in the entire visible region with an energy band gap of 5.09 eV, which is an essential requirement for a nonlinear optical crystal. Thermal stability of the grown γ-glycine crystal was determined using the thermo gravimetric and differential thermal analyses. The NLO activity of γ-glycine was confirmed by the Kurtz powder technique using Nd:YAG laser and the grown crystal exhibits high relative conversion efficiency when compared to potassium dihydrogen phosphate (KDP).
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 05/2011; 79(5):1123-7. · 2.10 Impact Factor
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ABSTRACT: The organic material 2-methylamino-5-chlorobenzophenone single crystal has been grown by modified vertical Bridgman technique using the single wall ampoule with nano translation. The grown crystal was confirmed by single crystal and powder X-ray diffraction analyses. Fourier transform infrared analysis was used to identify the functional groups present in the grown crystal. High resolution X-ray diffraction studies show the crystalline perfection of the grown crystal. The optical property of the grown crystal was analyzed by UV-vis-NIR and photoluminescence spectral studies. The thermal behavior of the grown crystal was analyzed by thermogravimetric and differential thermal analyses. The dielectric measurements of the grown crystal were carried out with different frequencies and temperatures and the results indicate an increase in dielectric and conductivity parameters with the increase of temperature at all frequencies. The microhardness measurements were performed to analyze the mechanical property of the grown crystal.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 05/2011; 79(5):1443-8. · 2.10 Impact Factor
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ABSTRACT: Cu2+ and glycine doped L-arginine monohydrochloride monohydrate (LAHCl) single crystals were grown by slow solvent evaporation technique. The grown single crystals were confirmed by X-ray diffraction study and the interaction of dopants with LAHCl molecule was identified in Fourier transform infrared spectra. The crystalline perfection of pure and doped crystals was analyzed by high resolution X-ray diffraction studies. Vickers microhardness and UV-visible spectroscopy were carried out respectively to study the mechanical stability and optical transmittance of pure and doped LAHCl single crystals. He-Ne laser of wavelength 632.8 nm was used to measure refractive index and birefringence of grown crystals. The second harmonic generation efficiency was also measured for pure and doped LAHCl single crystals using Nd:YAG laser.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 04/2011; 79(5):1017-23. · 2.10 Impact Factor
