Investigation on Nucleation Kinetics, Growth and Nonlinear Optical Properties of L-Cystine Hydrochloride Crystal

The semiorganic nonlinear optical crystal of amino-carboxyl acid family, L-cystine hydrochloride (LCHCl) was successfully grown from its aqueous solution by the slow evaporation solution growth method. The solubility, metastable zone width and induction period were determined for the first time experimentally and there by the possibility of growing bulk crystals of LCHCl using deionized water as solvent. The induction period was recorded for the different supersaturation ratios (S=1.2, 1.3, 1.4, and 1.5), which reveals that the induction period of LCHCl decreases with increase in supersaturation. The nucleation kinetic parameters such as critical free energy, change of volume free energy, critical radius, number of molecules in the critical nucleus and nucleation rate have been evaluated for LCHCl crystals. The interfacial energy values of LCHCl were determined for different supersaturation ratio by means of varying temperatures. The single crystal X-ray diffraction gives the lattice parameters value of the grown crystals. The second harmonic generation efficiency was confirmed by the Kurtz-Perry powder method. The laser damage threshold energy of the grown crystal indicates that grown crystal has excellent resistance to laser radiation also compared with known other nonlinear optical crystals

Structural, morphological, optical, and photoluminescence properties of nanocrystalline PbS thin films grown by chemical bath deposition

The transparent and nanocrystalline lead sulfide (PbS) thin films were prepared by the chemical bath deposition (CBD) technique onto glass substrates deposited at 80 °C using aqueous solution of lead acetate and thiourea. The X-ray diffraction pattern proves the crystallinity of deposited films that crystallize in the orthorhombic structure and preferred orientation. The energy band-gap and refractive index were estimated using UV–visible absorption spectra. The variation in band-gap with grain size showed blue-shift typical of electron quantum confinement. The effect of crystal ordering on refractive index was also evident by the linear increase of the refractive index with grain size. The PbS thin films were characterized by XRD, optical and SEM analysis

Preparation of nanocrystalline Cd-doped PbS thin films and their structural and optical properties

PbS and Cd-doped PbS nanocrystalline thin films prepared by the chemical bath deposition technique was deposited onto glass substrates at 80 °C. The aqueous solution containing Cd2+ and Pb2+ precursors was used to obtain good quality film deposits at optimized preparative parameters. The characterization of these films was performed using X-ray diffraction, optical absorption, photoluminescence properties, scanning electron microscopy and energy dispersive X-ray analyses to explore the properties of the PbS and Cd-doped PbS films. The prepared films were adherent to the substrate and well crystallized according to the cubic structure, which displayed a preferred orientation. According to the X-ray diffraction analysis, the crystallite size of the films decreased from 74 nm to 64 nm with increasing Cd doping. The optical properties were determined from ultraviolet-visible spectroscopy measurements in the absorbance energy range from 300â1200 nm. The UV-visible analysis shows that the band gap value of the PbS thin films increased from 2.12 eV to 2.65 eV by doping with Cd. Morphological analysis showed that the shape of the grains over the substrate surface was changed from a regular random orientation to an irregular shape with Cd doping. The energy dispersive X-ray analysis showed that the film contains Cd, Pb and S elements without any other impurities. Keywords: Thin films, Chemical synthesis, X-ray diffraction, Optical propertie

Studies on L-cystine hydrobromide single crystals for nonlinear optical applications

l-cystine hydrobromide (LCHBr) is a novel nonlinear optical material which has been synthesized and grown. The low-temperature solution growth technique was employed to grow the single crystal of LCHBr. The structure of the grown crystals was characterized by single-crystal XRD. The different functional groups of the grown LCHBr crystal are studied using FTIR spectroscopy. The transparent nature of the grown crystal was analysed by UV–Vis–NIR study. The mechanical strength of the grown crystal was analysed using microhardness study. The optical second harmonic generation conversion efficiency of the LCHBr crystal was studied using Nd:YAG laser. The laser damage threshold value of this grown crystal has been evaluated

Investigations on the nucleation kinetics of methyl-para-hydroxy benzoate single crystals

The solubility, metastable zone width and induction period have been determined for the solution grown methyl-para-hydroxy benzoate (MHB) single crystals. Nucleation parameters such as Gibbs free energy, radius of critical nucleus, critical free energy barrier and number of molecules in the critical nucleus and nucleation rate have also been investigated. Interfacial energy has been estimated using the experimentally determined induction period values. It is observed that the nucleation rate increases with the increase of supersaturation. The evaluated interfacial tension values are found to be comparable with the theoretical values. The growth parameters of MHB were optimized for the growth of large size crystals

Synthesis growth and characterization of L-Valinium Picrate a new nonlinear optical crystal

New nonlinear optical (NLO) single crystal Of L-Valinium Picrate (LVP) was grown by slow evaporation solution growth technique at room temperature. The cell parameters of the grown crystal were estimated by single crystal X-ray diffraction analysis. The presence of functional groups was identified from Fourier transform infrared spectrum. The transmission and absorption spectra of this crystal show that the lower cut-off wavelength lies at 380 nm. Thermal analysis was performed to study the thermal stability of the grown crystal. The powder second harmonic generation efficiency of the grown crystal measured by Kurtz technique is 2 times efficient of Potassium dihydrogen orthophosphate (KDP)

Investigations on the nucleation kinetics of bis glycine sodium nitrate

The nucleation parameters such as, energy per unit volume, radius of critical nucleus, critical free energy barrier, number of molecules in the critical nucleus and nucleation rate have been evaluated for bis glycine sodium nitrate single crystals. The interfacial energy of the solution at various temperatures has been estimated from existing solubility data. The metastable zone width and induction period measurements have been carried out experimentally

GROWTH AND CHARACTERIZATION OF GLYCINE HYDROBROMIDE SINGLE CRYSTAL FOR NONLINEAR OPTICAL APPLICATIONS

Single crystals of a new semi-organic nonlinear optical material glycine hydrobromide were grown from solution by slow evaporation at room temperature. Good optical quality single crystals with dimensions 17×8×5 mm3 were obtained. The grown crystal had been confirmed by single-crystal X-ray diffraction and the vibrational frequencies of various functional groups in the crystals had been derived from Fourier transform infrared spectrum. The optical quality of the grown crystals was analyzed by the Ultraviolet visible spectrum method. The mechanical behavior of the grown crystal was evaluated by Vickers' micro-hardness indentation method. The nonlinear optical property of the crystal was confirmed by the Kurtz powder technique using Nd:YAG laser as a source

SYNTHESIS, GROWTH, STRUCTURAL, SPECTROSCOPIC, OPTICAL, THERMAL AND MECHANICAL STUDIES OF A SEMI-ORGANIC NONLINEAR OPTICAL CRYSTAL: L-GLUTAMIC ACID HYDROCHLORIDE

The semi-organic nonlinear optical single crystal of L-glutamic acid hydrochloride was grown by slow evaporation solution growth technique at room temperature. The cell parameters of the grown crystal were estimated by single crystal X-ray diffraction analysis. The presence of various functional groups was identified from Fourier transform infrared analysis. The transmission spectrum of this crystal show that the lower cut-off wavelength lies at 248 nm. Thermal analysis was performed to study the thermal stability of the grown crystal. The Kurtz powder second harmonic generation test shows that the crystal is a potential candidate for optical second harmonic generation. Mechanical properties of the grown crystal were determined and Vickers' hardness number was calculated

Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: L-valine hydrochloride

Single crystals of a new semiorganic nonlinear optical (NLO) material, L-valine hydrochloride (LVHCl), having dimensions up to 20mm x 6 mm x 4mm 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 degrees C. The powder second harmonic generation (SHG) efficiency of LVHCl is 1.7 times efficient as potassium dihydrogen phosphate (KDP)