A. Antony Joseph

Growth and spectroscopic characterization of a new organic nonlinear optical crystal: L-alaninium succinate.

A novel organic nonlinear optical (NLO) material, l-alaninium succinate, was synthesized by the standard method. The synthesized material was purified by repeated recrystallization. Single crystals were grown by slow evaporation technique using water as solvent. The grown crystals were characterized by FT-IR, FT-NMR and UV-vis-NIR techniques. The second harmonic generation (SHG) from the material was confirmed using Nd:YAG laser which shows that LAS has 23% SHG efficiency of that of the standard KDP. The UV-vis-NIR transmittance was recorded in the range from 190 to 1100nm. In this study, the lower cut-off is shifted towards UV region (190nm) which shows that LAS has good transmittance in region from 190 to 1100nm and it makes LAS for SHG. Functional groups present in the grown crystal were identified using FT-IR spectrum which gives confirmation of NH(3)(+) ion in LAS. The chemical structure of l-alaninium succinate was established by FT-NMR technique.

Crystal growth and comparative studies of XRD, spectral studies on new NLO crystals: L-Valine and L-valinium succinate.

Nonlinear optical single crystals of L-valine and L-valinium succinate were grown by slow evaporation solution growth method using water as the solvent. Purity of crystals was increased by the method of recrystallization. The grown crystals were analyzed by the single crystals X-ray diffraction pattern which proved that LVS belongs to orthorhombic crystals system. The presence of functional groups and modes of vibrations were identified by FT-IR spectroscopy. The chemical structure of crystals was established by FT-NMR technique. The transmission range of grown crystals was identified by UV-vis-NIR. The transmission region of LVS was more effective than LV which could be used for NLO applications. The nonlinear optical property of the grown crystals was confirmed by second harmonic generation test which shows the suitability of NLO applications.

Growth, spectral, optical and thermal characterization of new metallorganic crystal--bisthiourea nickel chloride.

The novel nonlinear optical single crystal of bisthiourea nickel chloride (BTNC) was grown successfully by slow evaporation technique using water as solvent. The lattice parameters of the grown crystal have been determined by X-ray diffraction studies. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. Presence of various functional groups of BTNC was identified through FTIR and Raman spectroscopic analyses. Optical absorbance spectrum recorded in the wavelength range of UV-vis-NIR revealed that this crystal has good optical transparency in the range 200-2000 nm. The second harmonic generation test of BTNC revealed the nonlinear nature of the crystal. The BTNC crystal was analyzed by differential thermal and thermo gravimetric analysis (DTA-TGA) to obtain its thermal stability.

Spectroscopic studies on the influence of 10 mol% of glycine on nonlinear optical crystal L-valinium picrate.

Nonlinear optics is a fascinating field, which plays a vital role in the emerging field of photonics and optoelectronics. A new nonlinear optical crystal of glycine mixed L-valine picrate (GVP) have been grown from saturated aqueous solution by slow evaporation method at a temperature of 36°C using a constant temperature bath of accuracy of ±0.01°C. The synthesized organic optical material has been purified by repeated recrystallization. Single crystal X-ray diffraction analysis has been made to determine the cell parameters and it confirms the crystal lattice to be orthorhombic. UV-vis-NIR spectrum have recorded for GVP crystals in the range from 190 nm to 1100 nm and it is found that the crystal has cut-off at 450 nm. Fourier transform infrared transmission has confirmed the presence of the functional group present in the title compound. The spectrum has been recorded by KBr pellet technique. The (1)H and (13)C NMR spectra have been recorded to elucidate the molecular structure of GVP crystals. The second harmonic generation (SHG) of the grown crystal have been confirmed by Kurtz-Perry method using Nd:YAG laser as source.

Studies on growth and spectral characterization of diglycine fumarate monohydrate single crystals

Single crystals of organic optical material, diglycine fumarate monohydrate (DGFM) has been synthesized and grown from solution by slow evaporation solution growth method. Purity of synthesized materials was increased by continuous recrystallization. The lattice parameters of the grown crystals are observed by X-ray diffraction method and the crystal system of grown crystal is identified as monoclinic. The optical transparency range has been investigated by UV-Vis-NIR spectroscopy method in the range between 190 and 1,100 nm. The presence of different modes of vibrations is analyzed using FT-IR technique. The carbon and hydrogen atmosphere in molecular structure of DGFM is investigated using FT-NMR method. The thermogravimetrrc analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) analysis shows that the grown crystal has very good thermal stability up to 263°C. The Kurtz-Perry powder SHG test has done for grown crystals.

RETRACTED: Crystal growth and spectroscopic characterization of Aloevera amino acid added lithium sulfate monohydrate: A non-linear optical crystal

Non-linear optical crystals of lithium sulfate monohydrate added with Aloevera amino acid were grown successfully by slow evaporation technique moderately at low cost. Initially the Aloevera amino acid extract was prepared from the 3 years old plant leaves and the amino acids present in that were identified by high performance liquid chromatography. The grown crystal was clear, transparent and they attained the size about 1.3×0.8×0.6 cm(3) within a time span of 20-25 days. The crystal was subjected to Fourier Transform Infrared Spectroscopy, UV-Vis-NIR, thermal and mechanical studies. Proton nuclear magnetic resonance, thin layer chromatography and colorimetric estimation techniques are carried out to confirm and identify the amino acid in the grown crystal.

Growth of Organic Nonlinear Optical Crystals from Solution

Investigations on the growth of good quality single crystals play an important role in the development of modern scientific world with advanced technology. Behind the development in every new solid state device and the explosion in solid state device, there stands a single crystal. Crystal growth is an important field of materials science, which involves controlled phase transformation. In the past few decades, there has been a growing interest in crystal growth process, particularly in view of the increasing demand for materials for technological applications (Brice, 1986). Researchers worldwide have always been in the search of new materials and their single crystal growth. Solids exist in two forms namely single crystals, polycrystalline and amorphous materials depending upon the arrangement of constituent molecules, atoms or ions. An ideal crystal is one, in which the surroundings of any atom would be exactly the same as the surroundings of every similar atom. Real crystals are finite and contain defects. However, single crystals are solids in the most uniform condition that can be attained and this is the basis for most of the uses of these crystals. The uniformity of single crystals can allow the transmission without the scattering of electro magnetic waves. The methods of growing crystals are very wide and mainly dictated by the characteristics of the material and its size (Buckley, 1951).