Structural, optical and dielectric studies of glycinium trifluoroacetate single crystal

An organic material glycinium trifluoroacetate (GTFA) has been re-synthesized and large single crystals have been grown by solution technique. Complete structure of GTFA has been redetermined from single crystal XRD data. FTIR confirmed the presence of various functional groups. Melting point (152.44 °C), thermal stability and specific heat were studied from TG/ DTA and DSC. In UV absorption spectra, a lower cutoff value as 220 nm and a wide band gap as 4.86 eV for GTFA were observed. The dielectric studies, dielectric constant and loss were measured at different temperatures (30-90 °C) in the frequency range 100 Hz-2 MHz.     

Studies on amino acid picrates: Crystal growth,structure and characterization of a new nonlinear optical material l-isoleucinium picrate

A series of l-amino acids, isoleucine, valine, glutamine, methionine, arginine, cystine and aspargine are employed to form picrates with picric acid (1:1). A comparison of cell parameters reveals that expected picrates are formed only in the case of l-valine and l-isoleucine. l-Isoleucinium picrate (LIP), a new nonlinear optical material was grown from aqueous medium by the slow evaporation of equimolar mixture of l-isoleucine and picric acid. The structure of the grown crystal as determined by single crystal XRD diffraction analysis reveals that it belongs to the monoclinic system with space group P2₁ and the cell parameter values are, a = 9.970(3) Å; b = 6.425(2) Å; c = 12.871(4) Å; β = 109.54(3)°; V = 770.0(4) Å³; Z = 2. The presence of functional groups in the LIP is confirmed by FT-IR vibrational patterns and the good crystallinity indicated by powder X-ray diffraction method. The relative second harmonic generation (SHG) efficiency measurements reveal that the LIP is a highly efficient nonlinear optical (NLO) material having an activity 16 times as that of the reference material potassium dihydrogen phosphate. The optical transparency has been studied using UV–vis spectrophotometer and the absorption is minimum in the visible region. Thermogravimetric and differential thermal analyses reveal the purity of the sample and no decomposition is observed up to the melting point.     

EPR and optical studies of Cu doped ammonium dihydrogen phosphate single crystals

Electron paramagnetic resonance (EPR) spectra of Cu²⁺ ion in ammonium dihydrogen phosphate are studied at liquid nitrogen temperature (77 K). Four magnetically inequivalent Cu²⁺ sites in the lattice are identified. The angular variation spectra of the crystal in the three orthogonal planes indicate that the paramagnetic impurity, Cu²⁺ enters the lattice substitutionally in place of NH₄⁺ ions. The spin Hamiltonian parameters are determined with the fitting of spectra to rhombic symmetry crystalline field. The ground state wave function of Cu²⁺ ion is constructed and found to be predominantly |x²-y²〉. The cubic field parameter (Dq) and tetragonal parameters (Ds and Dt) are determined from optical spectra at room temperature. By correlating EPR and optical absorption spectra, the bonding coefficients are calculated and nature of bonding of metal ion with different ligands in the crystal is discussed.     

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.     

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,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 novel semiorganic nonlinear optical potassium boro-succinate (KBS) single crystals

Single crystals of novel semiorganic material, potassium boro-succinate (KBS) have been grown from aqueous solution by slow evaporation technique. The lattice parameters for the grown crystals were determined by the single crystal X-ray diffraction analysis. The presence of functional groups was estimated qualitatively by using fourier transform infrared (FTIR) analysis. The optical absorption spectrum shows that the UV cut-off wavelength for the grown crystal is at 240 nm. The thermal stability of the KBS crystal was studied by using TG/DTA analysis. The dielectric constant and loss were studied as a function of frequency. Nonlinear optical properties (NLO) test was performed by using Kurtz powder technique.     

Synthesis, crystal growth and characterization of a metal-organic nonlinear optical tri-allylthiourea mercury chloride single crystals

Metal-organic nonlinear optical material tri-allylthiourea mercury chloride single crystal was grown using low temperature solution growth method. The growth parameters such as pH and temperature were optimized for getting colorless single crystals. The X-ray rocking curve measurement shows that the grown crystal was free from internal structural grain boundaries. The structural, spectral, optical and thermal properties of the grown specimen were studied using various characterization techniques. The defects present in the grown crystals were studied with chemical etching analysis. The results show that the grown crystals are suitable candidates for nonlinear optical applications.     

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.     

Studies on the growth aspects and characterization of sodium para-nitro phenolate single crystals for nonlinear optical applications

Using slow evaporation solution growth technique, single crystals of sodium para nitro phenolate have been grown from the solutions prepared from three different molecular ratios of para-nitro phenol and sodium hydroxide. Structural analyses were carried out by powder X-ray diffraction and Fourier transform infrared spectrum to conform the grown crystals. Thermal stability of the grown crystals was studied by thermogravimetric (TG) and differential thermal analyses (DTA). UV–vis spectral analysis has been carried out to find the cut off wavelength of the grown crystals. Variations in the cut off wavelengths have been observed. Nonlinear optical property has been confirmed by Kurtz powder technique. The observed optical properties have confirmed that the molar concentration of para nitro phenol influenced significantly on the linear and nonlinear optical properties.     

Structural, optical and electrical studies on amino acid based new GBC crystals having non linear optical response

Transparent crystals of α-glycine with barium nitrate and calcium nitrate (GBC) have been grown from aqueous solution by slow evaporation technique at room temperature. Crystals of size 22 × 25 × 4 mm³ have been obtained in 3-4 weeks time. The solubility of GBC has been determined in water. The grown crystal belongs to orthorhombic system with cell parameters a = 12.7321 A.U, b = 13.7752 A.U and c = 8.6002 A.U with unit cell volume of 1508.36 (A.U)³. Comparative IR and Raman studies indicate a molecule with a lack of center of symmetry. A wide transparency window useful for optoelectronic applications is indicated by the UV Studies. Using Nd:YAG laser (1064 nm), the optical second harmonic generation (SHG) conversion efficiency of GBC is found to be 0.702 times than that of standard KDP. On exposure to light the GBC crystals exhibit positive photoconductivity. I-V characteristics, dielectrics studies, electrical and Vickers micro hardness measurement have been carried out. The GBC crystal exhibits more mechanical strength compared to the reported GSN crystals.     

Synthesis, growth and characterization of novel second harmonic nonlinear chalcone crystal

Nonlinear optical (NLO) materials are useful in many of the industrial applications. New NLO chalcone derivative (2E)-3-[4-(methylsulfanyl)phenyl]-1-(4-nitrophenyl)prop-2-en-1-one (4N4MSP) crystals have been grown by slow evaporation technique at ambient temperature. The grown crystals were subjected to single crystal X-ray diffraction study. The crystal has noncentrosymmetric structure in the orthorhombic system with space group Aba2 and unit cell parameters a=14.0647(15) Å, b=33.738(4) Å and c=6.0039(6) Å. To confirm the presence of various functional groups in the compound, FT-IR spectrum was recorded. The crystal was subjected to TGA/DTA analysis to find its thermal stability. The grown crystals were characterized for their optical transmission and mechanical hardness. The second harmonic generation (SHG) efficiency of the crystal is obtained by classical powdered technique using Nd:YAG laser and its value is 28.57 times that of urea. The laser damage threshold for 4N4MSP crystal was determined using Q-switched Nd:YAG laser. The refractive index values for green and red wavelengths were measured by Brewster angle technique. The dielectric and electrical measurements were carried out to study the different polarization mechanism and conductivity of the crystal. Good thermal, mechanical, transmission and SHG response make it desirable for the NLO applications.     

Growth and characterization of an efficient semi organic single crystal: Sodium hydrogen oxalate monohydrate

A highly proficient nonlinear optical compound Sodium Hydrogen Oxalate Monohydrate (SHOM) single crystal under semi organic category has been grown-up by the process of slow solvent evaporation. The triclinic structure and cell parameters of SHOM was revealed from X-ray diffraction analysis. The examination of FTIR was done to determine the existence of various functional groups present in the SHOM crystal. The mechanical stability is evaluated from Vicker's microhardness tester and related mechanical parameters were assessed. The multiple shot laser damage threshold was examined to be 2.65 GW/cm². TG/DTA analysis is carried out to appraise the thermal limit of the grown material. The absorbance spectrum was analyzed from UV–vis analysis which verifies high transparency of the grown crystal and various optical constants were also estimated. The third order nonlinearity, two-photon absorption and self-defocussing effect of the grown material was established from the Z-Scan approach. The results favoring the materials suitability over nonlinear optical applications are reported.     

Synthesis,growth, structure,spectral, thermal and first-order molecular hyperpolarizability of benzophenone-2-furoyl hydrazone single crystal

Single crystals of benzophenone-2-furoyl hydrazone are grown by slow evaporation solution growth technique from ethanol at room temperature. It belongs to monoclinic system with the space group P2₁/c and the cell parameters are, a = 6.1631(3) Å, b = 13.1397(8) Å, c = 18.0030(11) Å and V = 1457.72(14) Å³. NMR spectral studies reveal the structure and powder XRD indicates the crystallinity of the specimen. The characteristic functional groups present in the molecule are confirmed by Fourier transform infrared spectroscopy. The crystals are transparent in the visible region having a lower optical cut-off at ∼406 nm and the band gap energies are estimated by the application of Kubelka–Munk algorithm. Thermal analysis by TG/DTA indicates the stability of the material. The scanning electron microscopy studies reveal the surface morphology of the as-grown crystal. Theoretical calculations were performed using Hartree–Fock method with 6-31G(d,p) as the basis set for to derive the optimized geometry, dipole moment and first-order molecular hyperpolarizability (β) values.     

Structural and vibrational studies of anilinium nitrate

The crystals of anilinium nitrate, , were obtained by slow evaporation of an aqueous solution. The crystals belong to the Pbca (no. 61) space group of orthorhombic system, Z=8, a=10.158(2), b=9.277(2), c=16.177(3) Å. Positively charged anilinium cations and anions are present in the structure. Powder FT IR and FT Raman spectra for normal and deuterated samples are discussed with respect to the crystal structure. DSC measurements do not indicate clearly on the occurrence of phase transition in the temperature region 113-293 K.     

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.     

Growth,structural, thermal,optical, dielectric,mechanical and laser damage threshold studies of nicotinium tartrate single crystals

An organic nonlinear optical nicotinium tartrate (NT) single crystal was grown by slow evaporation solution growth technique. The cell parameters of NT crystal were confirmed by single crystal and powder X-ray diffraction studies. The crystalline perfection of NT crystal was examined from HRXRD studies. The presence of functional groups was identified from FTIR spectral analysis. TGA and DSC studies revealed the thermal stability of NT crystal. UV–vis-NIR spectral studies showed that the NT crystal has wide transmission window in the entire visible region. The dielectric study on NT crystal established the normal dielectric behavior. The mechanical strength of NT crystal was studied by Vickers’ microhardness test. The laser damage threshold value of NT crystal was measured using Nd:YAG laser. The relative SHG efficiency of NT was measured to be 1.1 times that of KDP.     

Reflection and vibrational spectra of SbSCl0.1I0.9 crystals in the ferroelectric phase-transition region

SbSCl_0.1I_0.9 crystals were grown from the vapor phase and reflection spectra were recorded using a Fourier-transform IR spectrometer. The optical parameters and optical functions along the c axis were calculated using an improved Kramers–Kronig technique with two confining spectral limits. The reflection spectra were analyzed using the oscillator parameter fitting technique for comparison of results. The vibrational frequencies ω_L and ω_T were evaluated. The ferroelectric phase-transition temperature was estimated as 330 K for SbSCl_0.1I_0.9 from experimental reflection measurements and theoretical investigation of the potential energy of Sb atoms for B_1u soft normal modes of SbSI and SbSCl_0.1I_0.9 crystals.     

Growth aspects,spectral, thermal and hardness studies of rare earth cerium(III)nitrate doped zinc(tris) thiourea sulphate single crystals

Single crystals of pure and cerium(III)nitrate doped zinc(tris) thiourea sulphate (ZTS) were grown from aqueous solution by slow evaporation method. The cell parameters of the grown crystals were determined by single crystal X-ray diffraction analysis. Powder X-ray diffraction patterns were recorded and indexed for the structural confirmation. The presence of functional group in the compound has been confirmed by FTIR analysis. UV–vis absorption spectrum has been recorded to determine the cut-off wavelength of the crystal. TGA/DTA studies show thermal stability of the grown crystals. SEM-EDX analysis revealed the incorporation of the impurity (Ce³⁺) into ZTS crystals. The microhardness study reveals that the hardness number (H_v) increases with load for all the grown crystals of this work. From the values of work hardening coefficients, it was concluded that pure and cerium nitrate doped ZTS crystals belong to the category of soft materials. The second harmonic generation of cerium(III)nitrate doped ZTS crystals was confirmed by Kurtz–Perry powder method using Nd:YAG laser.