C. Ramachandra Raja

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.

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.

Growth and spectral characterization of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate - a semi organic NLO material.

Semi-organic non-linear optical single crystals of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate crystals were grown by slow evaporation solution growth technique, at room temperature, using de-ionized water as solvent. The modes of vibrations of different molecular groups present in the grown crystal were identified by FT-IR technique. The optical absorbance/transmittance was recorded in the wavelength range of 190-1100 nm. Thermal properties of the grown crystal were studied by thermo gravimetric analysis and differential thermal analysis. The melting point of the grown crystal was estimated by differential scanning calorimetric analysis. The inclusion of the dopant (EDTA) was confirmed by colorimetric estimation method. The second harmonic generation efficiency is about 30% of potassium dihydrogen orthophosphate.

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.

Synthesis, growth and characterization of cadmium manganese thiocyanate (CMTC) crystal

Single crystals of cadmium manganese thiocyanate, CdMn(SCN)4 (CMTC) have been successfully synthesized and grown by slow evaporation solution growth technique using water as solvent at room temperature. The crystal was characterized by different techniques for finding its suitability for device fabrications. From the single crystal XRD the crystal system was identified as tetragonal. The functional groups were identified from FTIR analysis. The optical studies have been carried out and found that the tendency of transmission observed from the specimen with respect to the wavelength of light is practically more suitable for the present trends in communication engineering. From the thermal analysis the decomposing temperature of the grown crystal is more significant when compared with the studies performed earlier.

Influence of sol–gel derived strontium–cerium co-substitution in fluorohydroxyapatite and its in-vitro bioactivity

The present study is to investigate the influence of Sr2+ and Ce3+ ions in the structure of fluorohydroxyapatite (FHA) (Ca10(PO4)6F0.5(OH)1.5), a partial substitution of fluorine ion in hydroxyapatite. Co-substitution of Sr2+ and Ce3+ ions improves the osteoblast cell response, an important factor which stimulates the bone formation surrounding the implant material. Sol–gel derived fluorohydroxyapatite samples were co-substituted with Sr2+ and Ce3+ ions [xSr/yCe-FHA, where x = 5–40 mol% of Sr2+ and y = 5–20 mol% of Ce3+]. The intensity variation and shift of Fourier transform infrared bands observed after the co-substitution of Sr2+ and Ce3+ ions confirmed the doping. The X-ray diffraction shows the decrease in crystallite size with Ce3+ concentration and aids in forming beta-tri calcium phosphate and cerium-oxide (CeO) phases. Co-substitution of Sr2+ and Ce3+ increases the microhardness and fracture toughness, while micro structural analysis reveals the decrease in grain size. In-vitro bioactivity studies were conducted on samples using human osteosarcoma MG63 cells to investigate the osteoblast cell response. Co-substitution of cations in fluorohydroxyapatite by sol–gel method influenced the structure, phase formation, mechanical property, and grain size. These factors due to addition of Sr2+ and Ce3+ ions in fluorohydroxyapatite are attributed to the improvement of cell viability and alkaline phosphatase (ALP) activity.Graphical abstractXRD patterns confirm co-substitution of strontium and cerium ions in fluorohydroxyapatite.Co-substitution of Sr2+ and Ce3+ ions in FHA enhances in-vitro bioactivity.

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.

Synthesis, growth and characterization of a new nonlinear optical crystal: Glycinium hydrogen squarate (GHS)

Single crystals of glycinium hydrogen squarate (GHS) have been successfully synthesized and purity of the material has been increased by repeated recrystallization process. Single crystals were grown by slow evaporation solution growth technique using water and ethanol as solvents at room temperature. Then the grown crystal was characterized by different techniques for finding its suitability for device fabrications. The grown crystal was characterized by single crystal XRD, powder XRD, FT-IR, UV-Vis-NIR, (1)H NMR, (13)C NMR, SHG and DTA/TGA analyses respectively. From the single crystal XRD diffraction, the crystal system was identified as monoclinic. The presence of functional groups were identified by FT-IR analysis. The UV transparency cut-off wavelength of the grown crystal occurs at 342nm. (1)H NMR and (13)C NMR spectroscopic studies were employed to elucidate the structure of the grown crystal. The second harmonic generation efficiency test by Kurtz-Perry technique showed positive result. The decomposition temperature of the grown crystal was studied by DTA/TGA analysis. The results observed from the characterization analyses show its suitability for NLO applications.

Studies on the synthesis, spectral, optical and thermal properties of l-Valine Zinc Sulphate: An organic inorganic hybrid nonlinear optical crystal

Nonlinear optical (NLO) organic inorganic hybrid l-Valine Zinc Sulphate (LVZS) was synthesized and single crystals were obtained from saturated aqueous solution by slow evaporation method at 36°C using a constant temperature bath (CTB) with an accuracy of ±0.01°C. This crystal is reported with its characterization by single crystal and powder XRD, FTIR, UV-Vis-NIR, TG/DTA analysis and SHG test. Single crystal XRD study reveals that LVZS crystallizes in monoclinic system with the lattice constants a=9.969(3) Å, b=7.238(3) Å, c=24.334(9) Å and cell volume is 1736.00Å(3). Sharp peaks observed in powder X-ray diffraction studies confirm the high degree of crystallinity of grown crystal. The incorporation of sulphate ion with l-valine is confirmed by FTIR spectrum in LVZS crystal(.) A remarkable increase in optical transparency has been observed in LVZS when compared to l-valine and zinc sulphate heptahydrate Thermal properties of LVZS have been reported by using TG/DTA analysis. Kurtz powder second harmonic generation (SHG) test confirms NLO property of the crystal and SHG efficiency of LVZS was found to be 1.34 times more than pure l-valine.