Spectral,thermal, optical and dielectric characterization of tris(tetraethylammonium) pentabromozincate(II) monohydrate crystals

Tris(tetraethylammonium) pentabromozincate(II) monohydrate, is a new semiorganic compound synthesized and crystallized by slow evaporation solution growth method at room temperature. The formation of the compound in the stoichiometric ratio was confirmed by elemental analysis. The crystalline nature of the compound was confirmed by powder X-ray diffraction method and the crystal system was found to be triclinic. The absorption spectrum of the compound shows absorption at 247 nm and it has wide transparency in the visible region. The lower cut-off wavelength and the optical transmittance window of the compound were identified by optical transmittance study. The thermogravimetric and differential thermal (TG–DTA) analyses were studied to find out the thermal stability of the synthesized compound. The thermal anomalies observed in the differential scanning calorimetry (DSC) analysis indicate that the compound shows a first order phase transition. The FTIR spectrum was used to characterize the various chemical bonds and water molecule present in the compound. The nonlinear optical property (NLO) of the material was analyzed by modified Kurtz–Perry powder technique and found that it has SHG efficiency three times greater than that of KDP. The dielectric constant and dielectric loss of the compound decrease with increase in frequency.     

Synthesis,spectral and thermal characterization of Bis(diethylammonium) tetrachloromercurate(II)-An nonlinear optical material

A new semiorganic compound, bis(diethylammonium) tetrachloromercurate(II) was grown by slow evaporation solution growth technique at ambient temperature from its aqueous solution. The crystal system and the cell parameters have been identified from the powder X-ray diffraction pattern. The UV–visible absorption of the compound shows absorption at 246 nm and there is absorption observed in the entire visible region indicates that the compound can be used as a nonlinear optical material. The UV–visible transmittance spectrum of grown crystal shows a lower cut-off wavelength at 275 nm and it was found that the crystal is suitable for optoelectronic applications. Thermal studies were carried out to find out the thermal stability and confirm the stoichiometric ratio of the compound. The thermal anomalies in DSC study indicate the occurrence of first order transition in the compound at low temperatures. The FTIR spectrum of the compound characterizes various functional groups. The various kinds of protons and carbons were assigned through NMR (¹H and ¹³C) spectroscopic techniques. The SHG efficiency of the compound was studied by Kurtz-Perry power technique and observed that it has SHG efficiency 1.5 times greater than that of potassium dihydrogen phosphate (KDP). The dielectric constant and dielectric loss of the compound decreases with increase in frequency.     

Synthesis,spectral, thermal and optical characterization of benzyltributylammonium trichlorobarium(II) monohydrate crystal

A new nonlinear optical semiorganic crystal, benzyltributylammonium trichlorobarium(II) monohydrate was grown by slow evaporation solution growth method at ambient temperature. The powder X-ray diffraction pattern of the crystal confirms its crystallinity. The absorption spectrum of the material shows a peak at 265 nm and no absorption observed in the entire visible region indicates that the compound can be used as a nonlinear optical material. The optical transmittance spectrum of the grown crystal shows a lower cut-off wavelength at 235 nm with transparency of 88%. Thermal stability of the crystal was studied by thermogravimetry-differential thermogravimetry and differential thermal analyses (TG-DTG and DTA). The differential scanning calorimetry (DSC) analysis shows thermal anomalies in the heating and cooling cycles that indicates the occurrence of a first order phase transition. The various characteristics absorption chemical bands and BaCl₃⁻ vibration were assigned through fourier transform infrared (FTIR) spectral analysis. The second harmonic generation efficiency (SHG) of the grown crystal was analyzed by Kurtz–Perry powder technique using Nd:YAG laser. The dielectric constant and dielectric loss of the compound decrease with increase in frequency.     

Optical,spectral and thermal properties of organic nonlinear optical single crystal: 2,3-Dimethoxy-10-oxostrychnidinium hydrogen oxalate dihydrate

The potential organic nonlinear optical single crystal of 2,3-dimethoxy-10-oxostrychnidinium hydrogen oxalate dihydrate has been grown by slow evaporation solution growth technique (SEST) using ethanol–water solution at room temperature. The powder X-ray diffraction study reveals that the crystal belongs to orthorhombic system with non-centrosymmetric space group P2₁2₁2₁ and the cell parameters are a = 7.61 Å, b = 10.73 Å, c = 29.49 Å, V = 2410.75 Å³. The functional groups of the synthesized compound have been identified by FT-Raman and FTIR analyses. Photoluminescence spectroscopy study is determined to explore its efficacy towards device fabrications. Birefringence measurement has been carried out in order to analyze the optical homogeneity of the grown crystal. The optical constants such as reflectance (R) and extinction coefficient (K) have been determined from the transmittance data. The relative second harmonic efficiency of the compound is found to be 4 times greater than that of KDP. DTA-DSC measurements indicate that the crystal is thermally stable up to 174 °C.     

2-Phenylethylammonium p-hydroxybenzoate: Growth,structural, spectral,thermal, optical and mechanical characterization

An efficient nonlinear optical single crystal of 2-phenylethylammonium p-hydroxybenzoate (2PPHB) was grown from aqueous solution by slow evaporation solution growth method. Single crystal X-ray diffraction studies confirmed that 2PPHB crystallizes in orthorhombic crystal system with non-centrosymmetric space group of Pna2₁. The presence of functional groups in the synthesized compound was identified by FTIR spectral analysis. The grown crystals were thermally stable up to 155 °C. UV–vis absorption, photoluminescence and birefringence optical properties of grown crystal were explored. The laser induced surface damage threshold and relative second harmonic generation properties of the grown crystal were studied using Q-switched Nd:YAG laser. The variation of dielectric properties of the grown crystal with frequency was investigated for different temperatures. The mechanical response of the crystal was studied by Vicker's microhardness technique.     

Synthesis,spectral, thermal,optical and dielectric studies on 4-dimethylaminopyridinium picrate crystals

Single crystal of 4-dimethylaminopyridinium picrate was grown by slow evaporation solution growth method. The optical properties of the crystal were studied by using UV–vis absorption and transmittance studies. The emission spectrum indicates that the crystal shows green and red fluorescence emissions. The band gap energy of the crystal was calculated and it is found to be 2.05 eV. The thermal stability of the crystal was studied using thermogravimetry-differential thermal (TG-DTA) analyses. The thermal anomalies observed in the differential scanning calorimetry (DSC) heating and cooling cycles indicate the occurrence of a first order phase transition. FTIR spectrum was used to confirm the presence of various functional groups in the crystal. The synthesized crystal shows SHG efficiency 32 times greater than that of potassium dihydrogen phosphate (KDP). The dielectric constant and dielectric loss of the crystal decreases with increases in frequency.     

Growth,structural, spectral,optical and electrical properties of 2-aminophenol single crystals

Good quality single crystals of 2-aminophenol were grown by slow evaporation solution growth technique at room temperature. Crystal structure and crystalline nature was determined by X-ray diffraction studies. Prescence of functional groups in the crystal was confirmed by FT-IR analysis. UV transmittance study shows the large transmittance in the entire visible region. Dielectric constant and loss for the crystals were taken at different tempeature. Photoconductivity study exhibits positive nature of the grown crytal. DC conductivity studies were also carried out for the grown crystal.     

Synthesis,growth and characterization of non-linear optical material: l-Tryptophan p-nitrophenol (LTPNP) single crystal

A new nonlinear optical organic crystal l-tryptophan p-nitrophenol (LTPNP) of dimension 19 mm × 2 mm × 1.5 mm has been grown from an aqueous solution for the first time by slow evaporation technique at ambient temperature. The crystal structure of LTPNP was confirmed by single crystal X-ray diffraction. LTPNP crystallizes in non-centrosymmetric monoclinic system with space group P₂₁. The recorded FTIR spectrum confirms the presence of various functional groups in the grown crystal and confirms the formation of LTPNP. Thermal stability and melting temperature of the LTPNP crystal were identified from TG/DTA analysis. The optical absorption study confirms the suitability of the crystal for device applications. LTPNP exhibits SHG efficiency over 1.7 orders of magnitude higher than that of urea and 4 orders of magnitude higher than that of KDP.     

Growth, optical, dielectric and ESR studies on tetrathiourea mercury(II) tetrathiocyanato manganate(II): An organometallic complex NLO crystal

Single crystals of tetrathiourea mercury(II) tetrathiocyanato manganate(II); Hg(N₂H₄CS)₄Mn(SCN)₄, (TMTM) were grown by slow solvent evaporation technique. The grown crystals were confirmed by single crystal and powder X-ray diffraction analysis. The optical absorption spectrum of TMTM in a mixed solvent of acetone and water shows the near ultra-violet cut-off wavelength corresponding to the absorption maximum as 335 nm. FT-IR spectrum identifies the characteristic absorption bands of thiourea and thiocyanate in both middle and far infrared regions, which further confirm the incorporation of both the ligands in the resulting compound. The electron spin resonance spectrum of TMTM was recorded both at room temperature and −196 °C, which reveals that the Mn environment is symmetrical with respect to the NCS ligand distribution. It is also interesting to note that there is no hyperfine coupling between Mn nucleus and its free electrons at both room temperature and −196 °C. The dielectric constant as well as dielectric loss of the sample were calculated for varying frequencies under different temperatures.     

Crystalline perfection, optical and dielectric studies on l-histidine nitrate: A nonlinear optical material

Single crystals of l-histidine nitrate (LHN), a recently investigated nonlinear optical material, were grown by conventional solution technique. Crystal structure and vibrational modes of the grown crystals were confirmed by powder X-ray diffractometry and FT-Raman spectrometry, respectively. Crystalline perfection of the grown crystals was evaluated by employing an in-house developed high-resolution X-ray diffractometer (HRXRD) and it was found that the grown crystals were free from structural grain boundaries and the perfection was reasonably good. However, HRXRD could reveal the fact that the crystals contain predominantly the interstitial point defects. The birefringence was measured over a range of wavelength between 5480 and 5630 Å and it was found that its value is nearly constant and 10 times higher than that of KDP. The optical band gap was found to be ∼3.73 eV. The photoluminescence excitation and emission spectra for single crystals were recorded. The SHG efficiencies of LHN samples of different particle sizes were measured by the Kurtz and Perry technique and they removed the ambiguity in the values reported differently in the literature. Dielectric properties were studied as a function of temperature over a wide range of frequency. The optical and dielectric studies along with the crystalline perfection reveal that the LHN crystal could be a good candidate for nonlinear optical devices.     

Studies on vibrational,thermal, optical,dielectric and mechanical properties of a molecular salt: 2-Methylimidazolium hydrogen succinate

Good quality single crystal of 2-methylimidazolium hydrogen succinate (2MISA) was grown by slow evaporation solution growth method. The grown crystal was investigated using various characterization techniques to study its properties. Single crystal of 2MISA was confirmed by single crystal XRD. The high resolution X-ray diffraction curve shows the structural perfection of the grown crystal. Factor group analysis predicts 153 possible modes of vibrations. IR and Raman measurements confirm the functional groups present in the title crystal. From the UV–vis spectrum the optical bandgap and refractive index were evaluated. The PL spectrum of the title compound shows green emission. Dielectric tensorial behavior of the grown single crystal was studied with varying frequencies. The thermal stability of 2MISA was analyzed using TGA/DTA measurements, which infer the thermally stability. Mechanical stability of the grown crystal was studied by Vickers hardness tester.     

Enhancement of second harmonic generation efficiency: Growth and characterization of magnesium(II)-doped tetrakis(thiourea)nickel(II) chloride crystals

The influence of magnesium doping on the properties of tetrakis(thiourea)nickel(II) chloride crystals has been described. The reduction in the intensity observed in powder X-ray diffraction of doped specimen and slight shifts in vibrational frequencies confirm the lattice stress as a result of doping. Surface morphological changes due to doping of the alkaline earth metal are observed by scanning electron microscopy. The incorporation of Mg(II) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy. Lattice parameters are determined by single crystal XRD analysis. The thermogravimetric and differential thermal analysis studies reveal the purity of the materials and no decomposition is observed up to the melting point. The crystal is further characterized by Kurtz powder technique and dielectric studies.     

Growth,structural, spectral and optical studies on 2,4-dinitrophenol organic single crystal

Single crystals of 2,4-dinitrophenol were grown by slow evaporation solution growth technique in room temperature. Crystallinity of the grown crystal was confirmed by powder X-ray diffraction technique. UV transmission study shows the good optical transmission in the entire visible region. The dielectric loss is very low at high frequency which shows that the crystal contains low level defects. Photoconductivity reveals the positive nature of the photocurrent in these crystals. The powder second harmonic generation test was also carried out using Q-switched Nd:YAG laser.     

Synthesis,crystal growth and characterisation of 2-aminomethylpyridinium picrate (2-ampp)-a charge transfer molecular complex and organic nonlinear optical material

Single crystals of 2-aminomethylpyridinium picrate (2-AMPP) were grown by slow evaporation-solution growth technique at room temperature. The cell and structural parameters of the grown crystal were determined by single crystal X-ray diffraction analysis. The characteristic functional groups in the compound were identified from Fourier transform infrared spectroscopy. The transmission and absorption spectra of this crystal show that the lower cut-off wavelength lies at 360 nm. Thermal analysis was performed to study the thermal stability of the grown crystal. The powder second harmonic generation efficiency of the grown crystal measured by Kurtz technique is 2 times efficient than potassium dihydrogen orthophosphate (KDP). Vicker's microhardness test showed that the hardness value increases with increasing the applied load up to 50 g. The dielectric measurements of the compound in the frequency region from 50 Hz to 5 MHz showed that the material has lesser defects and can be used for optical application.     

Growth and characterization of organic nonlinear optical material: 5-Nitroindole (5NI) for optical applications

Single crystals of organic nonlinear optical material 5-Nitroindole (5NI) has been grown by slow cooling solution growth technique using methanol as a solvent. The grown crystal was subjected to single crystal X-ray diffraction technique to determine the lattice parameters. Fourier transform infrared spectrum (FTIR) was recorded to identify the presence of functional groups. The optical properties such as the optical band gap, extinction coefficient (k), refractive index (n) and optical conductivity (σ) were calculated. The optical band gap of 5NI is 2.33 eV. The melting point and thermal stability of the crystal was analyzed from TG/DTA studies. Dielectric studies were carried out at different temperatures and frequencies.     

Growth and characterization of bis(thiourea) zinc carbonate (BTZC) a new nonlinear optical material by solution growth slow evaporation technique

A new semi-organic nonlinear optical bis(thiourea) zinc carbonate (BTZC) material has been synthesized. BTZC single crystals were grown from aqueous solution by slow evaporation method. The grown crystals were characterized by single crystal X-ray diffraction (XRD), powder XRD, FTIR, UV–visible, thermal, and second harmonic generation (SHG) analysis. Single crystal XRD study has been carried out to identify the lattice parameters. FTIR studies confirm the functional groups present in the grown crystal. Optical transmission studies have confirmed that the grown crystal is highly transparent. Thermo gravimetric and differential thermal analyses reveal the good thermal stability of the material. The SHG conversion efficiency of BTZC was determined using Kurtz powder technique and found 1.3 times more than that of KDP.     

Optical, thermal, dielectric and ferroelectric behaviour of sodium acid phthalate (SAP) single crystals

Sodium acid phthalate (SAP), an efficient semi-organic crystal having dimensions 17×8×2 mm³ has been grown from aqueous solution by slow evaporation technique at room temperature within the period of 2 weeks. The lattice parameters of the grown crystals were determined using single-crystal X-ray diffraction analysis. The presence of functional groups was estimated qualitatively by Fourier transform infrared (FTIR) analysis. The band gap energy was determined using optical absorption studies. The TG/DTA analysis reveals that the SAP crystal is thermally stable up to 141.6 °C. The dielectric constant and dielectric loss was studied as a function of frequency and the corresponding activation energy (E_a) has been calculated for the grown crystal. Scanning electron microscope studies enunciate the ferroelectric domain patterns of the SAP crystal. Ferroelectric property of the grown crystal was confirmed by hysteresis loop studies.     

A study of thermal, dielectric and magnetic properties of strontium malonate crystals

Crystals of strontium malonate (SrC₃H₂O₄) were grown in silica gel by the single diffusion technique. The thermo gravimetric (TG), differential thermal analysis (DTA) and differential scanning calorimetric (DSC) studies were carried out to investigate the thermal stability of the crystal. The dielectric behavior of the title compound crystal was investigated by measuring the dielectric parameters - dielectric constant, dielectric loss and AC conductivity as a function of four frequencies −1 kHz, 10 kHz, 100 kHz and 1 MHz at temperatures ranging from 50 to 170 °C. Results indicate that the title compound is thermally stable up to about 409 °C and is a promising low ε_r-value dielectric material. The magnetic behavior of the crystal was also explored using a vibrating sample magnetometer.     

Growth and characterization of semi organic nonlinear optical l-Valine Ferric Chloride single crystal by solution growth technique

l-Valine Ferric Chloride single crystal is a new semi organic nonlinear optical material. It has been grown from a mixture of aqueous solutions of l-Valine and Ferric Chloride by slow evaporation solution growth technique at room temperature for the first time. Single crystal XRD analysis revealed that the crystal system belongs to Cubic P with cell parameters are a = 24.38 Å, b = 24.38 Å, c = 24.38 Å and volume is 14,485 Å³. The UV spectrum shows existence of wide transparency window suitable for optoelectronic applications. Thermal stability and melting temperature of the as grown crystal was identified from TG-DTA analysis. Spectroscopic studies have been carried out for analyzing the presence of functional groups, thermal stability and phase transition of the grown crystal. The dielectric loss and the dielectric constant of the crystals were measured as a function of frequency. Photoluminescence study was carried out for grown crystals and the maximum emission occurs has good optical transmission in the entire visible region. Second harmonic generation (SHG) conversion efficiency has been estimated.