Search

Objectives: To calculate the optical and structural parameters of the copper sodium tartrate (CuNaT) crystal for investigating its usefulness in the non-linear optics, it was analyzed by XRD and optical studies. Methods : A good nonlinear optical CuNaT crystal was grown by silica gel medium. The fundamental factors to prepare the silica gel for the controlled and defect - free growth of the CuNaT crystal are gel pH, gel density and gel setting period. Findings:The non-centro symmetric structure with refined lattice parameters: a = 7.7230 A, b = 20.2964 A, c = 7.9896 A and the required functional groups: O-H, M-O,C-O and C=O bonds of CuNaT were recognized by the XRD and FTIR studies. Novelty: The monoclinic structure and space group P21 of grown CuNaT crystal was non-identical to the orthorhombic structure of the copper tartrate crystal was enabled to identify its novel structure. The NLO competence of the CuNaT was 0.38 times relative to KDP and of higher LDT value than the KDP, provided its novel optical properties. Applications: The strong intensity emission peaks recorded at 297 nm and 380 nm in the photoluminescence spectrum and the lower absorption edge at 334 nm in the UV spectrum of the CuNaT crystal exhibited its potential use in non-linear optics. Keywords: Single crystal XRD; FTIR; UVVisNIR; PL; SHG; LDT

A new copper (II) sodium (I) tartrate trihydrate with general formula of [(Na2 Cu2 (C4H4O6) 3 (H2O) 3) 3H2O] (NaCuT) was synthesized and grown from the silica gel. The monoclinic structure and the space group P21 of the as-grown crystal are calculated and non identical with copper tartrate is found by the single crystal and powder X-ray diffraction studies. The presence of O H, C O, C O, C H and M O bonds were confirmed by Raman FTIR spectroscopy. The UV spectrum showed the transmittance in the Ultra-Violet region about the lower cutoff wavelength at 310.5 nm which makes the material to be suitable for UV filters. Different decomposition stages with respect to the mass loss of the copper sodium tartrate were studied by thermo gravimetric analysis. Occurrence of the improved electrical conductivity by the pi electrons of the C O and O-H----O groups of the CuNaT crystal was established by the dielectric studies. From Z-scan studies, the present sample proved its suitability for non linear optical applications.

A new organic optical limiting material, ethylenediaminium picrate (EDAPA) was synthesized through acid base reaction and grown as single crystals by solvent evaporation method. Single crystal XRD analysis showed that EDAPA crystallizes in orthorhombic system with Cmca as space group. The formation of charge transfer complex during the reaction of ethylenediamine and picric acid was strongly evident through the recorded Fourier Transform Infra Red (FTIR), Raman and Nuclear Magnetic Resonance (NMR) spectrum. Thermal (TG–DTA and DSC) curves indicated that the material possesses high thermal stability with decomposition temperature at 243 °C. Optical (UV–Visible-NIR) analysis showed that the grown crystal was found to be transparent in the entire visible and NIR region. Z-scan studies with intense short pulse (532 nm, 5 ns, 100 µJ) excitations, revealed that EDAPA exhibited two photon absorption behaviour and the nonlinear absorption coefficient was found to be two orders of magnitude higher than some of the known optical limiter like Cu nano glasses. EDAPA exhibited a strong optical limiting action with low limiting threshold which make them a potential candidate for eye and photosensitive component protection against intense short pulse lasers.

The newly synthesized CdNa2?2C2O4?2H2O crystals having a size of 0.30 × 0.25 × 0.20 mm3 were grown by the single-diffusion reaction method in the silica gel medium at 28?C temperature. The crystalline nature of crystals was determined in 20 days by 1) varying the concentrations of the feed solutions and the gel pH level, 2) changing the specific gravity of the feed solution, and 3) changing the gel aging period. The crystals were characterized by using the methods such as powder X-ray diffraction, FTIR, UV, SEM-EDAX, TGA/DTA, and micro-hardness test. The structure of as-grown crystals was determined by the powder crystal XRD patterns. FTIR & SEM-EDAX spectral analyses were used to confirm the presence of the required functional groups of as grown crystals. UV absorption spectrum, the absorption peaks at 224.64 nanometer, determined the energy gap. TGA/DTA thermo gram was used to detect the thermal stability of sodium mixed cadmium oxalate dihydrate crystals. The present grown crystals were brittle and also plastic in nature was identified by Vickers micro-hardness test.

Gamma bis glycinium oxalate (GBGOx) crystal was synthesized and grown by slow evaporation solution technique. The structure of pure GBGOx crystal has been examined by single crystal X-ray diffraction analysis. The confirmation with single crystal XRD reveals that the crystal belongs to monoclinic system with space group C 2 . The FTIR spectrum was recorded to identify the expected functional groups. UV–vis-spectrum shows the lower cut off wavelength and 80% of transmittance in the UV–vis region. The photoluminescence measurement shows that the material is suitable for photonic devices. Preliminary measurement of green light emission using Kurtz powder technique indicates that their second harmonic generation (SHG) efficiency. The microhardness analysis revealed that the grown crystal belongs to soft material category. The encouraging results show that the GBGOx crystals have great potential applications in optical devices.

A nonlinear optical 3-hydroxy anthranilic acid (3-HAA) is synthesized, and a single crystal is grown by slow evaporation method. The structural perfection of the grown crystal is predicted by the powder X-ray diffraction (XRD) analysis. The presence of functional group is confirmed by Fourier transform infrared (FTIR) spectroscopy. The dielectric behavior of the grown crystal is analyzed for different frequencies for the temperature range 40–150°C.

2-Amino-5-nitropyridinium halides (2A5NPBr)/(2A5NPCl) were synthesized by dissolving 2-amino-5-nitropyridine in hydrobromic/hydrochloric acid. Nanoparticles of 2A5NPBr and 2A5NPCl were attained by hydrothermal method. For comparison and estimation of mechanical properties, single crystals of the samples were grown by slow evaporation process. SEM analysis shows the formation of nanoparticles of 2A5NPBr and 2A5NPCl with average grain size of 50 and 100[Formula: see text]nm, respectively. UV-Vis analysis reveals that the materials possess low cut-off wavelength and a wide optical transmission window. By Vickers test, the Meyer index (n) was estimated to be 1.33 for 2A5NPBr and 2.49 for 2A5NPCl crystals. The SHG efficiency of 2A5NPBr and 2A5NPCl nanoparticles was calculated to be 1.5 and 4.3 times that of well known NLO material KDP. The role of cations in demonstrating the desired NLO properties were discussed in detail.

In the title compounds, 4-aminopyridinium 4-aminobenzoate dihydrate, C(7)H(6)NO(2)(-).C(5)H(7)N(2)(+).2H(2)O, (I), and 4-aminopyridinium nicotinate, C(5)H(7)N(2)(+).C(6)H(4)NO(2)(-), (II), the aromatic N atoms of the 4-aminopyridinium cations are protonated. In (I), the asymmetric unit is composed of two 4-aminopyridinium cations, two 4-aminobenzoate anions and four water molecules, and the compound crystallizes in a noncentrosymmetric space group. The two sets of independent molecules of (I) are related by a centre of symmetry which is not part of the space group. In (I), the protonated pyridinium ring H atoms are involved in bifurcated hydrogen bonding with carboxylate O atoms to form an R(1)(2)(4) ring motif. The water molecules link the ions to form a two-dimensional network along the (101) plane. In (II), an intramolecular bifurcated hydrogen bond generates an R(1)(2)(4) ring motif and inter-ion hydrogen bonding generates an R(4)(2)(16) ring motif. The packing of adduct (II) is consolidated via N-H...O and N-H...N hydrogen bonds to form a two-dimensional network along the (102) plane.

In the title compound, [Ni(2)(CO(3))(C(5)H(6)N(2))(8)(H(2)O)]Cl(2)·5H(2)O, one of the the Ni(II) ions is six-coordinated in a distorted octa-hedral geometry, with the equatorial plane defined by four pyridine N atoms from four amino-pyridine ligands, the axial positions being occupied by one water O and a carbonate O atom. The other Ni(II) ion is also six-coordinated, by four other pyridine N atoms from four other amino-pyridine ligands and two carbonate O atoms to complete a distorted octa-hedral geometry. In the crystal structure, mol-ecules are linked into an infinite three-dimensional network by O-H⋯O, N-H⋯Cl, N-H⋯O, O-H⋯N, C-H⋯O, C-H⋯N and C/N-H⋯π inter-actions involving the pyridine rings.

In the title compound, (C(5)H(7)N(2))(2)[CoCl(4)], the cobalt(II) ion is coordinated by four chloride ions in a slightly distorted tetra-hedral geometry. The crystal packing is stabilized by inter-molecular N-H⋯Cl hydrogen bonding, forming a three-dimensional network. The crystal was a non-merohedral twin emulating tetra-gonal symmetry, but being in fact ortho-rhom-bic.