Growth, optical, mechanical and thermal studies of diglycine cadmium chloride single crystal

Transparent single crystals of diglycine cadmium chloride were grown by slow evaporation solution technique. To confirm the crystal structure, the grown crystals were subjected to single crystal as well as powder X-ray diffraction measurements and the structure was found to be monoclinic. The elemental analysis was carried out by energy dispersive X-ray spectroscopy. The crystalline perfection of the grown crystal was assessed by high-resolution X-ray diffractometry and found that the crystal quality is fairly good. The optical study reveals that the grown crystal is highly transparent in the region 250?C900?nm. Thermal studies reveal that the grown crystal is stable up to 245?°C. The michrohardness analysis revealed that the grown crystal belongs to soft material category. The high dielectric constant (>30) and low loss (<0.01) value also confirms that the grown crystal is a good candidate for device fabrications.     

Growth,optical, thermal,dielectric and mechanical studies of sodium hydrogen succinate single crystal

Sodium hydrogen succinate, an alkali metallo-organic third-order nonlinear optical crystal, had been grown successfully using aqueous solution by slow evaporation technique at room temperature. Transparent single crystals were selected and subjected to single-crystal X-ray diffraction analysis to identify lattice parameters, space group and morphology. The grown crystal was further subjected to powder X-ray diffraction to analyze the crystalline quality, UV–Vis–NIR spectral analysis to reveal optical transparency, FTIR spectroscopy for confirmation of the functional group analysis and TG–DTG/DSC analysis to determine the thermal stability. The dielectric constant and dielectric loss were studied as a function of frequency at different temperatures, and the results were discussed. The mechanical properties were calculated by Vickers microhardness test, and the third-order nonlinear optical parameters such as nonlinear refractive index, nonlinear absorption coefficient and real and imaginary parts of the third-order nonlinear optical susceptibility were determined by Z-scan technique.     

Thermal,FTIR and microhardness studies of bisthiourea-urea single crystal

Single crystals of a new nonlinear optical material, bisthiourea-urea have been grown from aqueous solution by slow evaporation technique with a period of 4 weeks. The structure of the grown crystals was confirmed by X-ray diffraction (XRD). The presence of title compound in the crystal lattice has been qualitatively determined by FTIR analysis. The mechanical properties and thermal stability of the grown crystals were evaluated by Vickers microhardness test and TG and DTG, respectively.     

Thermal study of l-alanine, l-threonine, and taurine crystals related to hydrogen bonding

In this study l-alanine, l-threonine, and taurine crystals were characterized through dilatometric technique and thermogravimetric and differential thermal analysis. The dilatometric analysis shows that the thermal expansion of the crystals is correlated with the strengths of local hydrogen bonding in the amino acid structures at room temperature. Thermogravimetric analysis and differential thermal analysis of the l-alanine, taurine, and l-threonine crystals have been performed at high temperatures. No clear correlation between the hydrogen bonding strengths and endothermic peak positions was observed.     

Growth, structural, optical, thermal and mechanical properties of ammonium pentaborate single crystal

Nonlinear optical single crystals of ammonium pentaborate (APB) were grown by the slow cooling method from aqueous solution. Grown crystal was characterized by powder X-ray diffraction (PXRD) and FT-IR spectral analysis. Perfection of the grown crystal was evaluated by high-resolution X-ray diffractometry (HRXRD). The effect of nylon threading on the perfection of the grown bigger crystal was also studied by HRXRD. The range and percentage of optical transmission was ascertained by recording UV-vis-NIR spectrum. Thermal properties were investigated by TG-DTA and DSC analyses. Its mechanical hardness was estimated by Vickers microhardness tester.     

Growth and characterization of nonlinear optical material: l-alanine thiourea

The title compound of l-alanine thiourea, a semi organic material, has been grown from slow evaporation solution growth technique at room temperature. It is a potential material for nonlinear optical applications. The grown single crystals have been analyzed using powder X-ray diffraction. It belongs to monoclinic crystal system, and its lattice dimensions were determined. The presence of functional groups was identified from FTIR spectral analysis. The title compound has good optical transmission in the entire visible region. Thermal stability of the grown crystal was investigated by thermogravimetric and differential thermal analysis.     

Bulk size crystal growth,spectral, optical,luminescence, thermal,mechanical, and dielectric properties of organic single crystal

Single crystal of 2-[2-(4-methoxy-phenyl)-vinyl]-1-methylstilbazolium iodide (4MESI) was grown by the slow evaporation method. Single-crystal X-ray diffraction analysis reveals the formation of the title crystal. The density of the grown crystals was measured, and it was compared with theoretically calculated value. The FTIR and powder XRD of 4MESI were performed at room temperature. The different types of proton present in the crystal structure have been confirmed by NMR spectroscopic study. UV–Vis–NIR spectral studies reveal that 4MESI crystals are good optical transparency in the entire visible region. The photoluminescence spectrum of 4MESI shows violet and blue emission. Thermal stability and behavior of the grown crystal have been investigated by TG and DTG analysis. It shows that the grown crystal has melting point at 243 °C. Mechanical hardness of the grown crystals was estimated by Vickers microhardness tester. The grown crystals were also characterized by chemical etching and dielectric studies, and the results are discussed in detail.     

Synthesis, growth, thermal, optical, mechanical and dielectric studies of N-succinopyridine

Organic nonlinear optical (NLO) material, N-succinopyridine (NSP), was synthesised and bulk single crystals were grown from aqueous solution using isothermal solvent evaporation technique. The stoichiometric form of NSP has been confirmed by carbon–hydrogen–nitrogen analysis. NSP crystallizes in orthorhombic system with non-centrosymmetric space group P2₁2₁2₁ and unit cell dimensions a = 7.721(2) Å, b = 7.762(3) Å, c = 14.951(3) Å. The thermal stability, thermal decomposition and specific heat capacity of NSP have been investigated by thermogravimetric/differential thermal analysis, differential scanning calorimetric (DSC) analysis and modulated DSC analysis. A wide transparency window, 294–1,100 nm, useful for optoelectronic applications is indicated by UV–Vis–NIR studies. The NLO second harmonic generation efficiency analysis using Nd:YAG laser (1,064 nm) revealed that the SHG efficiency of NSP is about 1.2 times higher than that of standard potassium dihydrogen phosphate powder of comparable size and more importantly that it is phase-matchable. The room temperature mechanical behaviours of NSP have been tested using Vicker’s microhardness tester and the results were analysed through classical Mayer’s law. The dielectric behaviours such as dielectric constant, dielectric loss and ac conductivity of NSP single crystal have also been investigated as a function of frequency (20 Hz–1 MHz) and temperature (308–358 K).     

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 20 mm x 6 mm x 4 mm 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).     

Single crystal EPR and optical absorption studies of Cu2+ ion in L-arginine sulphophosphate monohydrate--a nonlinear optical crystal

The EPR spectra of Cu2+ ion in L-arginine sulphophosphate monohydrate (LASP), a nonlinear optical material (NLO) have been studied at room temperature. Two magnetically inequivalent interstitial Cu2+ sites in the lattice were identified. The principal values of g- and A-tensors indicate that the symmetry of the electrostatic field around the Cu2+ ion is rhombic. Bonding parameters have been evaluated and the ground state wave function of Cu2+ ion is constructed. The ground state is found to be an admixure of x2 - y2 and 3z2 - r2 orbitals. By correlating EPR and optical absorption spectra the crystal field parameters have been evaluated.     

Thermochemical properties of l-alanine nitrate and l-alanine ethyl ester nitrate

Two inorganic derivatives of l-α-alanine, namely alanine nitrate (AlaNO₃) and alanine ethyl ester nitrate (AlaEthNO₃), were synthesized and studied by combustion calorimetry and differential scanning calorimetry (DSC). The enthalpies of combustion and formation in the condensed state, as well as the thermal behavior and stability in the temperature range of 25–250 °C for AlaNO₃ and ?70–250 °C for AlaEthNO₃, were determined. The increasing of the stability of the derivatives compared with that of the alanine was observed. The melting decomposition temperatures and the corresponding enthalpies of transitions were evidenced. FT-IR determinations were used to identify functional groups of the studied compounds. The UV–vis spectral study was carried out to test the optical transmitting property. Additional polarimetric measurements which confirmed the chiral nature of the two nitrates were performed.     

Effect of sunset yellow dye on morphological,optical, dielectric,thermal and mechanical properties of KDP crystal

Herein, we describe the growth and morphology of well-defined dyed crystals of KH₂PO₄ (potassium dihydrogen orthophosphate; KDP) containing organic azo (sunset yellow; SSY) dye in the {1 0 1} & {0 0 1} pyramidal growth sectors. An understanding on selective dye inclusion in various growth sector of host crystal is proposed, which will help in designing novel tailor-made dyed photonic crystals. The structural analysis and the identification of various functional groups present in as grown KDP crystals were carried out using powder XRD, FTIR and Raman studies. Solid state transmittance spectra for dyed KDP crystals displayed three absorption peaks at 230 nm, 311 nm and 477 nm, which were blue shifted for SSY dye in KDP crystal relative to neutral aqueous solution of SSY dye. These blue shifts in the absorption maxima confirm the successful incorporation of sunset yellow dye into the pyramidal growth sectors of dyed KDP crystals. The band around 409 nm in the photoluminescence emission spectrum indicates a violet emission. SSY dye doped KDP crystals showed enhanced dielectric properties and thermal stability as compared to pure KDP crystal. The mechanical strength of the KDP crystals estimated using Vickers microhardness test was found to decrease with the increase in SSY dye doping.     

Thermal and optical studies on some monomer and polymer diacetylenes

We describe the thermal and optical studies of some diacetylene molecules which were specially designed in an attempt to reduce the temperature at which the mesophase appears. Original studies were on symmetrical molecules and these were extended to include typical liquid crystal molecules with diacetylenes providing a polymeric backbone and unsymmetrically substituted diacetylenes including Schiffs bases with long alkyl chains.     

肼基硫代甲酸酯配合物的合成、晶体结构、光谱及三阶非线性光 学性质研究

报道三种有推拉电子基团的肼基硫代酸酯衍生物配体(HL^1^～^3)。此类配体与二价过渡金属离子配位时脱去一质子,形成D-M-D和A-M-A(D=给体,M=金属,A=受体)类型、含有共轭体系的中性配合物。本文集中研究了该类配体的镍、铜、钯、铂配合物的IR、磁化率、ESR谱,电子光谱和三阶非线性光学性质,通过光谱研究初步确定了它们均为平面正方形构型配合物,文中还报道了CuL2^1的晶体结构。晶体属P1空间群,a=0.7835(2),b=1.0530(2),c=1.1816(2)nm,α=100.61(3),β=92.38(3),γ=110.00(3)ⅲ,Z=1,最终的R因子为0.063。通过晶体结构测试,进一步确定铜配合物的结构为平面构型。     

Synthesis, growth, optical, mechanical, dielectric and thermal properties of 4-chloro-4'-chlorobenzylidene aniline single crystal

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.     

Studies on crystal growth, vibrational and optical properties of organic nonlinear optical crystal: p-aminoazobenzene

p-Aminoazobenzene (p-AAZB), an organic nonlinear optical (NLO) crystal having good optical quality has been grown by slow evaporation solution technique using ethanol as a solvent. Solubility studies were performed at different temperatures. The structural characterization of the grown crystals was carried out by X-ray diffraction. Group theoretical analysis was carried out to calculate the number of modes of vibration. The lowering of the wave numbers of azo group suggests the existence of strong intermolecular N-H...H hydrogen bonding. This has been analysed based on the vibrational spectral features. Optical absorption studies show the effective transmission in the entire UV-vis region. The second harmonic generation results show the suitability of this material for NLO applications.     

Liquid single crystal elastomers (lsce) - mechanical optical and electric properties

Liquid crystal elastomers can be macroscopically ordered with respect to the director by applying a mechanical field similar to electric/magnetic field effects of low molar mass liquid crystals. Introducing network anisotropy a priori by the synthesis, uniformly aligned nematic or smectic elastomers are available without external mechanical field. These LSCE's combine optical properties of single crystals with entropy elasticity of elastomers. Due to uniform director orientation without defects, the LSCE's exhibit excellent transparency which makes them applicable for optical elements. Non-linear optical properties can be easily optimized by attaching suitable I.c.-moieties to the polymer network. On the other hand, due to the rubber elasticity of the LSCE's, electromechanical effects can be observed, e. g. piezoelectricity of chiral smectic C-LSCE's.