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Single crystals of lead zinc niobate-lead titanate (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 for x = 8% and 9% have been grown by flux method using Lead Oxide (PbO) as flux. Low scan rate XRD has been carried out to investigate on the structural influence of the compositional variations in the grown crystals. Transmission spectra in the range of UV-Vis-Near IR and mid IR regions have been carried out to understand the distortions caused in the BO6 octahedral lattice. Morphological aspects of as-grown PZN-PT crystals have also been investigated. Dielectric measurements clearly explained the dependence of Tc and diffusiveness with PT content. The values of Pr and Ecobtained from P-E loops suggest the presence of ordered domain state in these PZN-PT single crystals. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A semi-organic nonlinear optical L-proline dimercuricchloride (LPDMC) material has been synthesized. LPDMC single crystals were grown from aqueous solution by a slow cooling method. Good quality single crystals of size 19×6×3 mm have been grown over a period of 3 weeks. The grown crystals have been subjected to single crystal X-ray diffraction analysis to determine the cell parameters. The title compound crystallizes in the triclinic system with a noncentrosymmetric space group P1 and with unit-cell parameters a=7.2742(4) Å, b=9.4472(5) Å, c=10.4767(6) Å, α=108.621(3), β=107.260(2), γ=97.353(2) and volume=631.51(6) Å. Optical and dielectric properties of the crystals have been studied. The thermal stability of the crystals was determined by thermogravimetric analysis/differential thermal analysis. The second harmonic generation efficiency of the crystals was obtained by the classical powder technique using a Nd:YAG laser and it is found to be 2.5 times that of potassium dihydrogen phosphate. [ABSTRACT FROM AUTHOR]

Abstract: Piezoelectric single crystals of 0.58Pb(Sc1/2Nb1/2)–0.42PbTiO3 and Nb5+-doped PSN–PT have been grown using flux technique. It is believed that the addition of Nb5+ creates lead vacancy in order to compensate charge neutrality. The structural distortion that occured in the doped crystals has been revealed through broadening of some peaks in X-ray diffraction studies. Niobium content that increased from 0.50 to 1.00 mol% might have induced more defect dipoles associated with . This plays a significant role in improving the ferroelectric, dielectric and piezoelectric properties. Our observations clearly show an increase in the spontaneous polarization , dielectric constant at room temperature, degree of diffuseness and transition temperature and also a decrease in coercive field. The reasons behind these enhanced electrical properties are discussed in detail. [Copyright &y& Elsevier]

Abstract: Single crystals of l-lysine hydrochloride dihydrate (LLHCD), a nonlinear optical material, have been grown by slow cooling technique from its aqueous solution. LLHCD was found to be highly soluble in water. The grown crystals have been subjected to single crystal X-ray diffraction to confirm the structure and to estimate the lattice parameters. The vibrational structure of the molecule is elucidated from FTIR spectra. Thermal analysis revealed the thermal stability of the grown crystals. The optical transmittance spectrum shows that the material possesses good optical transparency in the entire visible region with a UV cut-off wavelength at 228nm. The mechanical properties of the grown crystal have been studied using Vicker''s microhardness test. The laser damage threshold of 52.25MW/cm2 has been measured by irradiating Q-switched Nd:YAG laser (1064nm). [Copyright &y& Elsevier]

Abstract: We report here the effect of growth parameters on the growth process of Pb[(Sc1/2 Nb1/2)0.58Ti0.42]O3 (PSN–PT) single crystals in the flux method. PSN–PT single crystals have been grown by the slow-cooling technique using PbO+B2O3 flux. The size of the crystals varies from 1 to 4mm, mostly showing regular cubic shape. Pure perovskite phase formation has been confirmed by X-ray diffraction technique. Rietveld analysis reveals that the grown crystals have the monoclinic structure in the Cm space group. This is consistent with the recent reports revealing monoclinic structure in relaxor-based ferroelectric single crystals. Scanning electron and optical microscopic studies have been used to analyze the surface morphology of the crystals and to predict the structural changes during growth. Dielectric measurement of (001) showed a dielectric maximum near 234°C (T c), which is higher than that of PZN–PT and PMN–PT. [Copyright &y& Elsevier]

Abstract: Bulk single crystals of l-arginine maleate dihydrate (LAMD), an organic nonlinear optical material, have been grown from aqueous solution by slow cooling technique. Single crystals of size 48×33×7 mm3 were grown over a growth period of 3 weeks. Since LAMD has high solubility in water, the growth parameters have been optimized for the reproducible growth of good quality crystals. The cell parameters were estimated by powder X-ray diffraction analysis. FTIR analysis was used to confirm the presence of various functional groups in the grown crystal. Thermal behavior of the grown crystal was investigated by DTA and TGA. The mechanical property of the grown crystal has been studied using Vicker''s microhardness tester. The etching studies have been carried out on the grown crystals. The powder technique of Kurtz and Perry confirms the NLO property of the grown crystal and the SHG efficiency of LAMD was found to be 1.4 times that of KDP crystal. [Copyright &y& Elsevier]

Single crystals of semi-organic non-linear optical (NLO) l-histidine tetrafluoroborate (l-HFB) have been successfully grown from three different pH (1.8, 3.2, and 4.2) solutions by evaporation and temperature lowering method. Solubility of l-HFB crystals (grown from different solution pH) has been estimated. Crystals grown at lower pH values are observed to have higher solubility. The grown crystals have been subjected to powder X-ray diffraction studies to identify the crystalline nature. Single crystal X-ray diffractometer was utilized to measure unit cell parameter and morphology of grown crystal. The FTIR spectra taken for the crystals grown at different pH values show variations in the peak intensity. The NLO property is found to be varying with the change in pH values. The differential scanning calorimetry confirms the stability of the crystal up to 250°C. The microhardness studies reveal the changes in the mechanical property of the crystals grown from different pH values. [Copyright &y& Elsevier]

Single crystals of Co-doped B1-xSrxTiO3 (Co:BST) have been grown by high-temperature solution growth technique. The dopant has significant effect on the growth parameters and considerably reduced the twin formation in the grown crystal. Bulk single crystals of dimensions 5×5×4 mm3 have been grown with optimized growth parameters. Layer growth and vein-like structure patterns, indicative of 2D nucleation mechanism, have been observed on the grown crystals. The presence of dopant in the grown crystals was confirmed by EDX analysis. For lower doping concentration (0.1 mol%), the crystal possesses tetragonal structure and changes to cubic for higher dopant level (1 and 5 mol%) Co doping in BST increases the dielectric constant values and decreases the Curie temperature (Tc). The spontaneous polarization (Ps) value for 0.1 mol% of Co-doped BST crystal is measured to be 22 μc/cm2 and the value decreases with increasing Co concentration. [Copyright &y& Elsevier]

Reinvestigation on the structures of silver (Ag) co-ordinated thiourea single crystals and the discussion of thermal and dielectric studies as a reply to "the comments on the paper: Crystal design, thermal and dielectric behavior of novel silver (Ag) co-ordinated thiourea single crystals" by Dr. B.R. Srinivasan. [ABSTRACT FROM AUTHOR]

• TuAgN crystals were harvested by slow evaporation solution growth method. • The crystal materials belong to Triclinic (P-1) and Tetragonal (I4 1) systems. • Anions and cations are linked by intermolecular N-H...O hydrogen bonds. • DTA peaks at 155 °C and 142 °C shows the melting points of TuAgN crystals. • TuAgN (1:1) show comparatively large dielectric constant value ~150 at 1 MHz. Novel silver co-ordianted thiourea adducts was synthesized by mechanochemical stirring process. Structural data of TuAgN (1:1) and TuAgN (4:1) were collected with the help of single crystal X-ray diffractometer and their unique structural properties were studied and compared. The ratio of the compounds 1:1 and 4:1 represents the mole ratio of thiourea and silver nitrate which has taken for the synthesis. i.e. TuAgN (1:1) indicates, 1 mole of thiourea and 1 mole of silver nitrate and TuAgN (4:1) reveals, 4 mole of thiourea and 1 mole of silver nitrate. The crystalline materials belong to Triclinic and Tetragonal systems with a space group of P-1 and I4 1 respectively. In both the crystal systems, a single Ag atom co-ordinate with three thiourea ligands and the chain is continued through Ag to Ag interactions. TG/DTA study provides the details of thermal stability and thermal decomposition behavior of the crystals. Electrical characterizations like dielectric constant, dielectric loss and their importance were studied at different temperatures (40, 60 and 80 °C) in the frequency range from 50 Hz to 5 MHz. [ABSTRACT FROM AUTHOR]

Lead free piezoelectric single crystals of sodium potassium niobate (K0.5Na0.5)NbO3 (KNN) were grown by high-temperature solution method using two different fluxes; one with a mixture of NaF and KF and other with addition of B2O3 along with the mixture. In the present study, the growth of KNN crystals without B2O3 flux and the same with B2O3 flux were compared. It was found that additions of small amounts of B2O3 lowered the melting temperature of the solid solution and enabled better dielectric properties. Phase analysis showed that all samples were crystallized in pure orthorhombic perovskite phase. AFM morphological studies showed that the addition of B2O3 flux increased the roughness of the grown crystal. Further, addition of B2O3 flux slightly decreased the orthorhombic to tetragonal phase transition temperature T(O-T) and the Curie temperature TC. The ferroelectric behaviour of KNN single crystal has been investigated at room temperature. The crystal grown using B2O3 flux exhibited a remanent polarization (Pr) ∼ 32 μC/cm2 and coercive field (Ec) of ∼11.8 kV/cm whereas the crystal grown without the use of B2O3 flux had a remanent polarization (Pr) ∼ 36 μC/cm2 and coercive field (Ec) of ∼14.6 kV/cm. [ABSTRACT FROM AUTHOR]

Abstract: l-arginine trifluoroacetate, an organic nonlinear optical material, has been synthesized from aqueous solution. Bulk single crystal of dimension 57mm×5mm×3mm has been grown by temperature lowering technique. Powder X-ray diffraction studies confirmed the monoclinic structure of the grown l-arginine trifluoroacetate crystal. Linear optical property of the grown crystal has been studied by UV–vis spectrum. Dielectric response of the l-arginine trifluoroacetate crystal was analysed for different frequencies and temperatures in detail. Microhardness study on the sample reveals that the crystal possesses relatively higher hardness compared to many organic crystals. Thermal analyses confirmed that the l-arginine trifluoroacetate material is thermally stable upto 212°C. The etching studies have been performed to assess the perfection of the l-arginine trifluoroacetate crystal. Kurtz powder second harmonic generation test confirms the nonlinear optical properties of the as-grown l-arginine trifluoroacetate crystal. [Copyright &y& Elsevier]

Abstract: Large-size cesium triborate (CsB3O5:CBO) crystals were grown from self-flux solutions by top-seeded solution growth. The crystals have numerous scattering centers that were found to depend on the temperature from which the crystals were grown. The weight loss measurements revealed that more weight loss occurred at the growth temperature of 74mol% B2O3. During the cooling process (after growth) there is a possibility of the crystal being shifted to the off-stoichiometric composition because of cesium out-diffusion. To bring the crystals to near stoichiometric solutions, the vapor transport equilibration (VTE) process (post-growth heat treatment) was carried out and the scattering centers were reduced. The cesium atmosphere used in VTE processing was very important for the diffusion of cesium into the crystal and to bring the crystals to near stoichiometric composition. [Copyright &y& Elsevier]

Abstract: Effect of amino acids (l-leucine and isoleucine) doping on the growth aspects and ferroelectric properties of triglycine sulphate crystals has been studied. Pure and doped crystals were grown from aqueous solution by low temperature solution growth technique. The cell parameter values were found to significantly vary for doped crystals. Fourier transform infrared analysis confirmed the presence of functional groups in the grown crystal. Morphology study reveals that amino acid doping induces faster growth rate along b-direction leading to a wide b-plane and hence suitable for pyroelectric detector applications. Ferroelectric domain structure has been studied by atomic force microscopy and hysteresis measurements reveal an increase of coercive field due to the formation of single domain pattern. [Copyright &y& Elsevier]

Abstract: Single crystals of nonlinear optical l-arginine iodate (l-Arg·2HIO3) (C6H14N4O2·2HIO3), were successfully grown for the first time by the temperature-lowering method and also by the slow evaporation method at a constant temperature (30 °C) from its aqueous solution at pH value of 6. Crystals were of average dimensions 3×2.5×1.0 cm3 by optimizing the growth parameters. Initially, solubility studies were carried out for four different solvents such as water, water–methanol, water–ethanol, and water–acetone. Among the four solvents, the solubility of l-Arg·2HIO3 was found to be the highest in water and hence crystallization of l-Arg·2HIO3 was carried out from aqueous solution. Morphology studies reveal that the crystals grow with reasonable growth rate along the [100], [001], [110¯] and [011] direction. As-grown crystals were characterized by density measurement, X-ray powder diffraction studies, infrared spectrophotometer, UV–Vis spectrometer, laser induced damage threshold studies and nonlinear optical study. [Copyright &y& Elsevier]

Abstract: A new semiorganic nonlinear optical rubidium bis-dl-malato borate (RBMB) has been synthesized and single crystals were grown by slow cooling technique from aqueous solution. The grown crystals have been characterized by X-ray diffraction (single crystal XRD) to confirm the formation of the crystalline phases. FT-IR and FT-Raman spectroscopic analyses confirm the presence of all the functional groups in the grown crystals. TG-DTA studies reveal that the material is stable up to 230°C. The UV–vis transmission spectrum shows a lower cutoff wavelength of 230nm. The emission of SHG using Nd:YAG laser is confirmed by a modified Kurtz and Perry powder setup. [Copyright &y& Elsevier]

Abstract: l-Arginine diiodate (l-Arg·2HIO3) a new semi-organic nonlinear optical (NLO) material was synthesized by the standard method. The synthesized material was purified by repeated recrystallization process. Single crystals were grown by the slow evaporation and slow cooling methods. Crystal with excellent transparency were grown with maximum size of 20mm×10mm×10mm and the grown crystals were characterized by single crystal XRD, FT-IR, FT-Raman, TGA-DTA, hardness study, and UV–vis-NIR studies. The second harmonic generation (SHG) of the material was confirmed using Nd:YAG. The l-Arg·2HIO3 has NLO efficiency 1.3 times higher than the KDP crystal. Laser damage threshold studies revealed that the grown crystals possess high damage threshold values. [Copyright &y& Elsevier]

Abstract: Single crystals of bis-glycine sodium nitrate (BGSN), a semi-organic nonlinear optical (NLO) material, have been grown by slow cooling method. Good optical quality single crystals with dimensions up to 1.6×1.6×1.0cm3 are obtained. Using a single-crystal diffractometer, the morphology of BGSN crystal was identified. Powder X-ray diffraction confirms the crystalline nature of BGSN. The grown crystals were characterized by optical transmission spectrum (UV) and FTIR studies. The NLO property of the crystal was confirmed by Kurtz second harmonic generation (SHG) test, and the output power generated by the crystal was compared with that of KDP. The thermal stability of the crystal was studied by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Micro hardness study was carried out for different planes, and the anisotropy behavior of the crystal was observed. [Copyright &y& Elsevier]

Abstract: Single crystals of a new histidinium salt: l-histidinium trichloroacetate {abbreviated as LHTCA; [(C3N2H4)CH2CH(NH3)(CO2)]+CCl3COO−} were grown by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in a non-centrosymmetric space group P21 of monoclinic system with cell parameters a =5.4505(18)Å, b =25.769(8)Å, c =9.210(2)Å and β =99.98(2)°. The vibrational structure of the compound confirms the presence of various functional groups in the molecule. The UV–vis–NIR spectrum shows a good transparency in the whole of the region from ultraviolet to near IR. The Kurtz powder SHG measurement confirms the frequency doubling of the crystal. Thermal behaviour of the crystals has been investigated by DSC analysis. These preliminary results suggest that LHTCA crystal can act as a potential and promising candidate for frequency doubling applications even from the near UV region to the near IR. [Copyright &y& Elsevier]

Abstract: l-Histidine tetrafluoroborate (l-HFB) is a highly transparent monoclinic crystal with favourable properties of efficient frequency conversion. Single crystals have been grown successfully by a slow evaporation method. The solubility of the l-HFB crystal is very high in water when compared to other solvents like acetone or methanol. In this study, l-HFB crystals were grown from aqueous solution. The grown crystals have been subjected to X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), second harmonic generation and ultraviolet–visible spectral analyses. Thermogravimetric and differential scanning calorimetry analyses have been performed to study the thermal stability of the crystal. Capacitance and dielectric loss measurements were carried out and the dielectric constant was calculated at room temperature in the frequency range 1kHz–40MHz. The dielectric constant at room temperature remains constant for the entire frequency range. [Copyright &y& Elsevier]

Single crystals of non-linear optical l-threonine amino acid have been grown by slow evaporation and temperature-lowering methods from aqueous solution. As-grown crystals were characterized by powder X-ray diffraction analysis and the vibrational frequencies of various functional groups in the crystals have been derived from FTIR spectrum. The range and percentage of optical transmission is assertained by recording UV–VIS–NIR spectrum. Thermal behaviour of the crystals has been investigated by DSC and TGA analyses. The NLO property of the grown crystal has been confirmed by Kurtz-powder SHG test. [Copyright &y& Elsevier]

Single crystals of Rh-doped BaTiO3 have been grown by high-temperature solution growth technique. The dopant has significant effect on the growth parameters and crystal properties. Bulk single crystals of dimensions 5×5×4 mm3 have been grown with optimized growth conditions. Layer growth and vein-like structure patterns, indicative of 2D-nucleation mechanism, have been observed on the grown crystals. The dopant level in the grown crystals was estimated by EDX analysis. The crystals possess tetragonal structure and the tetragonality decreases for higher dopant concentration. Rh doping in BaTiO3 leads to decrease in dielectric constant and Curie temperature (Tc) values. [Copyright &y& Elsevier]

Single crystals of triglycine sulphate (TGS) modified with La3+, Ce3+ and Nd3+ have been grown from aqueous solutions by low-temperature solution growth method. The effect of rare earth ion dopants (La, Ce and Nd) on the ferroelectric properties of TGS is reported. Dielectric constant and dielectric loss have been measured for different frequencies. Dielectric measurements revealed that the dielectric constant of Ce-doped TGS increases rapidly at the transition temperature. Piezoelectric d33 coefficient has been measured for the rare earth ions modified TGS crystals. Among the three dopants, Nd-doped TGS possesses low dielectric constant and high pyroelectric coefficient suggesting that this can be a potential material for infrared detectors. [Copyright &y& Elsevier]

Single crystals of l-arginine tetrafluoroborate (l-AFB), a semi-organic NLO material, have been grown from aqueous solution. Since l-AFB is known to form highly viscous solution in water, growth by slow cooling has been difficult for optical quality crystals. In this study, highly transparent l-AFB crystals have been successfully grown by slow evaporation by keeping the saturated solution under special condition. The grown crystals were subjected to structural, optical and mechanical property studies. XRD studies reveal that l-AFB crystals possess orthorhombic structure. Fourier transform infrared absorption studies confirm the chemical constituents and presence of functional groups in the grown crystals. l-AFB crystals possess a higher hardness values compared to other semi-organic crystals. The linear and nonlinear optical properties of the grown crystals have also been studied. [Copyright &y& Elsevier]

A metal–insulator–semiconductor device structure has been successfully grown on GaN by using ferroelectric BaTiO3 (BTO) as an insulating layer. The GaN and BTO films of the GaN metal–ferroelectric–semiconductor (MFS) structures have been characterised using high-resolution X-ray diffraction, wide-angle X-ray diffraction and energy dispersive X-ray analysis. The electrical properties of fabricated Al/BaTiO3/GaN MFS structures have been characterised by high-frequency capacitance–voltage (C–V) measurement. C–V characteristics are remarkably improved for GaN MFS with a ferroelectric insulator when compared to other traditional oxide insulators. The fabricated GaN MFS structures approach inversion just for the applied bias of 5 V, which is mainly due to the high dielectric constant and large polarisation field of the gate ferroelectric layer. [Copyright &y& Elsevier]

Abstract: Single crystals of l-threonine, a nonlinear optical material, have been grown from solution by the temperature lowering technique. l-threonine was found to have extremely high solubility in water. Hence it was feasible to grow bulk crystals of l-threonine in aqueous solution. The cell parameters were estimated by powder X-ray diffraction analysis. The vibrational structure of the molecule is elucidated from FT-IR and FT-Raman spectra. Thermal analysis was performed to study the thermal stability of the grown crystals. The transmission spectra of l-threonine show that the lower UV cutoff wavelength lies at 220nm. Kurtz powder SHG measurements confirm the NLO property of the grown crystal. Microhardness studies have also been carried out on l-threonine crystals. [Copyright &y& Elsevier]

Abstract: A new nonlinear optical material, l-alanine acetate (l-AlAc) has been synthesized. Single crystals of l-AlAc have been grown by the slow cooling method. Bulk crystals have been grown with a solution pH of 3.0. The grown crystals were subjected to various characterization studies such as chemical etching, dielectric measurement, FTIR analysis, UV-visible spectrum and powder SHG test. The structure of the crystal was confirmed by single-crystal X-ray diffraction analysis. l-AlAc crystals exhibit better thermal and mechanical stability with improved optical properties. [Copyright &y& Elsevier]