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.     

Investigation of crystal structure and nonlinear optical properties of 2-methoxyanilinium nitrate

Single crystals of a new hybrid compound salt: 2-methoxyanilinium nitrate were prepared by slow evaporation at room temperature of diluted aqueous solutions containing 2-methoxyaniline with nitric acids. The compound crystallizes in a space group Pcab of orthorhombic system with cell parameters a = 8.8784 (6) Å, b = 10.6348 (7) Å, c = 18.3045 (7) Å, V = 1728.31 (17) ų at T = 100 K and Z = 8. The structure has been refined to an R-value of 0.044 for 1956 observed reflections using three-dimensional X-ray diffraction data. Third-order nonlinear optical susceptibility (χ^〈3〉) was measured by degenerate four wave mixing (DFWM) method at 532 nm. Third harmonic generation (THG) measurements at the 1064 nm were carried out for the 2-methoxyanilinium nitrate crystal with the following dimensions: 4 × 9 × 0.5 mm.     

Synthesis, growth, and characterization of a non-linear optical crystal-glycine lithium chloride

A new non-linear optical material, glycine lithium chloride, was synthesized and single crystals were grown by slow evaporation solution growth technique at constant temperature from its aqueous solution. Transparent and well-crystallized hexagonal prisms were obtained by controlled evaporation at a constant temperature of 45 °C. The grown crystals were characterized by X-ray diffraction methods, Fourier transforms infrared spectroscopy, and optical absorption spectrum. Single crystal X-ray diffraction analysis revealed that the crystal lattice of glycine lithium chloride is hexagonal with unit cell a = b = 7.023 Å, c = 5.478 Å, α = β = 90°, γ = 120°, V = 234 Å³. The dielectric response of the crystal with varying frequencies was studied. The second harmonic generation efficiency of the crystal was studied and is found to be larger than KDP.     

l-Cystine hydrochloride: A novel semi-organic nonlinear optical material for optical devices

A new semi-organic nonlinear optical (NLO) material l-cystine hydrochloride (LCHCl) was grown in large size measuring 19 × 5 × 3 mm³ by slow solvent evaporation technique for the first time in literature. The cell parameter values were determined by single crystal X-ray diffraction studies. Fourier Transform Infrared spectroscopic analysis was carried out on the grown sample to ascertain the fundamental functional groups. Thermal behavior of the grown LCHCl sample was analyzed by TG & DTA analysis. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester. The optical transmission studies and second harmonic generation (SHG) efficiency studies justified the device quality of the grown crystal and the SHG study reveals that the grown sample has nearly 1.2 times higher efficiency than that of potassium dihydrogen phosphate (KDP), a well known NLO material.     

Studies on the optical and mechanical properties of organic nonlinear optical 1-(4-fluorostyryl)-4-nitrostilbene (FNS) single crystal

A new organic nonlinear optical material 1-(4-fluorostyryl)-4-nitrostilbene (FNS) has been synthesized and single crystals of FNS were grown using solvent evaporation solution growth technique (SESGT) by 2-butanon solvent. Single crystal x-ray diffraction analysis reveals the unit cell parameters of the grown crystal are a = 9.494(4) Å, b = 9.864(2) Å, c = 19.501(7) Å and it belongs to monoclinic system with noncentrosymmetric space group. Optical transmittance of the grown crystal has been studied by UV-Vis-NIR spectrum. The optical properties of FNS have been studied by means of optical transmittance measurements in the wavelength range of 190–1100 nm The optical constants were calculated from the optical transmittance (T) data such as refractive index (n), extinction coefficient (k) and reflectance (R). The optical band gap (E_g) of FNS is 3.27 eV with direct transition. The complex dielectric (?) constant of the grown FNS crystal was determined. The second harmonic generation (SHG) efficiency of the grown FNS crystal has been studied by using Kurtz-Perry powder technique and it shows 12 times relatively greater than KDP.     

Thermal, mechanical, electrical, linear and nonlinear optical properties of a nonlinear optical l-ornithine monohydrochloride single crystal

Optically transparent semiorganic nonlinear optical bulk single crystal of l-ornithine monohydrochloride (LOMHCL) of dimension 11×3×2 mm³ has been grown from its aqueous solution by slow solvent evaporation technique. The grown crystal was characterized by powder X-ray diffraction to confirm the crystal structure. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopy technique. Thermal behavior of the grown crystals was studied by thermogravimetric analysis. The second harmonic generation (SHG) efficiency of LOMHCL was determined by Kurtz and Perry powder technique. The optical absorption study confirms the suitability of the crystal for device applications. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester. Dielectric and photoconductivity studies are also carried out for the grown samples.     

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.     

Growth and characterization of GSZS crystals with enhanced transparency window for non linear optical applications

Transparent crystals of novel non-linear optical material comprising of glycine sodium-zinc sulfate (GSZS) have been grown in our laboratory from solution by slow evaporation technique. Transparent crystals of dimensions (8 × 7 × 4 mm³) have been obtained in 3-4 weeks time. The solubility in water shows linear variation in temperatures range from 300 K to 350 K. The GSZS crystal exhibits orthorhombic symmetry with a = 5.418 A.U., b = 6.084 A.U and c = 3.497 A.U. The intense XRD peak is found at 25.43°. The presence of functional groups has been studied by FTIR analysis and verified by laser Raman spectra. Lower cutoff wavelength and enhanced transparency window with a typical energy gap of 5.85 eV are suggested by the UV measurements. The second harmonic generation (SHG) efficiency of GSZS is found to be 0.62 times than that of standard KDP using modified Kurtz and Perry technique. The GSZS crystal exhibits a normal dielectric behavior.     

Growth and physical properties of an organic crystal for NLO applications: Guanidinium phenyl arsonate (GPA)

Single crystals of organic material guanidinium phenyl arsonate (GPA) of size 28 × 14 × 10 mm³ were grown from propanol–water mixed solvent by slow solvent evaporation technique. The crystal belongs to monoclinic system with noncentrosymmetric space group Cc. The lattice parameter values of GPA crystals are a = 18.453 Å, b = 7.609 Å, c = 12.592 Å and β = 121.856°. The grown crystal was subjected to X-ray diffraction (XRD) study to identify its morphology and structure. Chemical etching study using propanol–water as etchant reveals the mechanism of growth. The formation of synthesized compound was confirmed by Fourier transform infrared (FT-IR) spectroscopy analysis. Optical transmittance and second harmonic generation (SHG) of the grown crystals were studied by UV–vis–NIR spectrum and Kurtz powder technique respectively. The transmittance of GPA has been used to calculate the refractive index ‘n’ and the extinction coefficient ‘k’. The laser induced surface damage threshold for the grown crystal was determined using Nd:YAG laser. The mechanical behavior of GPA was analyzed using Vickers microhardness test.     

Growth and characterization of a novel organic nonlinear optical material: l-alanine 2-furoic acid

l-alanine 2-furoic acid (LA2FA), a novel organic third order nonlinear optical material was grown by slow solvent evaporation technique at room temperature. The grown single crystals were characterized by XRD, spectral, thermal, optical, dielectric and third order nonlinear properties. LA2FA crystallizes into triclinic system with the space group P1. The cell parameters are found to be a = 3.97 Å, b = 7.09 Å, c = 10.69 Å, α = 73.61°, β = 83.57°, γ = 84.21° and V = 286 Å3. The modes of vibrations of different molecular groups present in LA2FA were identified by FTIR studies. The optical transparency of the grown crystals was investigated by UV–visible spectrum. The absorption spectrum reveals that the crystal has a high UV cut off of 245 nm and photonic band gap of 2.5 eV. The scanning electron microscope (SEM) study has been carried out to determine the surface morphology of the grown crystal. The thermal behavior of the crystal investigated using thermo gravimetric (TG) and differential thermal analysis (DTA) indicates that the material does not decompose before melting. The third order NLO property was studied in detail by z-scan technique.     

Growth and characterization of a new organic NLO material: Glycine nitrate

Single crystals of glycine nitrate [(C₂H₆NO₂)⁺ · (NO₃)⁻] were grown using submerged seed solution method. The crystals were characterized by using single crystal X-ray diffraction and density measurements. Spectroscopic, thermal and optical studies were carried out for analyzing the presence of the functional groups, thermal stability, decomposition and transparency of the sample. These studies showed that the crystals are thermally stable upto 145 °C and transparent for the fundamental and second harmonic generation of Nd:YAG (λ = 1064 nm) laser. Second harmonic generation (SHG) conversion efficiency was investigated to explore the NLO characteristics of this material. Microhardness and dielectric studies were also carried out.     

Crystal growth,structural, linear and nonlinear optical studies of 4-methyl-4′-N’-methylstilbazolium tosylate single crystals

Organic 4-methyl-4′-N’-methylstilbazolium tosylate, a new derivative of the stilbazolium tosylate family compound was synthesized by condensation method. The optical quality single crystals with dimension 5 mm × 4 mm × 2 mm were grown by slow evaporation technique at 40 °C. The crystal system and lattice parameters were found from single crystal X-ray diffraction studies. The optical transmittance, cut-off wavelength (402 nm) and band gap energy (3.09 eV) were estimated by UV–visible studies. The surface laser damage threshold study was carried out for MMST crystal using Nd:YAG laser. The third-order nonlinear optical susceptibility (χ³) for MMST crystal was estimated by employing Z-scan technique using 1064 nm laser.     

Studies on vibrational, dielectric, mechanical and thermal properties of organic nonlinear optical co-crystal: 2,6-diaminopyridinium-4-nitrophenolate-4-nitrophenol

This article presents the vibrational, dielectric, mechanical and thermal properties of 2,6-diaminopyridine-4-nitrophenolate-4-nitrophenol co-crystals (DAP:NP) grown by slow evaporation solution growth technique. It crystallizes in orthorhombic noncentrosymmetric space group Pna2₁ with cell dimension a=10.86 Å, b=12.00 Å and c=13.53 Å; α=β=γ=90° with V=1764 Å³. Functional groups present in the molecule have been identified from FTIR study. Dielectric constant (ε_r), dielectric loss (tanδ) and ac conductivity (σ_ac) behaviors of the crystals have been studied at different temperatures. Presence of piezoelectric resonance peaks at lower frequency in dielectric measurements may increase the electro-optic coefficient of the crystals. Mechanical strength and its parameters of the grown crystals have been determined by Vickers microhardness test. TG/DTA analysis shows the melting point of the material is 150 °C and it undergoes two stages of decomposition.     

Third order nonlinear optical properties of potassium dichromate single crystals by Z-scan technique

Single crystal of potassium dichromate (KDC) has been grown from aqueous solution by slow evaporation technique. The lattice parameters of the grown crystal were determined by X-ray diffraction analysis. The optical absorption studies reveal that the crystal has UV cut-off wavelength around 240 nm. Thermo gravimetric and differential thermal (TGA/DTA) studies revealed that the crystal thermally stable up to 397.1 °C. The mechanical strength of the grown crystal was carried out by Vickers micro hardness test. The crystal perfection was confirmed by etching studies. Third order nonlinear optical studies was performed using by single beam Z-scan technique using continuous Nd:YAG laser. Closed aperture Z-scan studies reveal the negative nonlinearity in the crystals and open aperture Z-scan reveals the saturation absorption. Also various parameters such as nonlinear refractive index n₂, absorption co-efficient β and nonlinear optical susceptibility χ⁽³⁾ were calculated for the grown crystal.     

Growth and design of novel nonlinear optical material (NLO) ⿿ Glycine barium nitrate potassium nitrate (GBNPN) crystal

A potentially useful semi organic nonlinear optical (NLO) material ? glycine with barium nitrate and potassium nitrate (GBNPN) has been synthesized by slow evaporation technique. Good transparent GBNPN crystals were obtained in a time span of 3 weeks. The grown crystals were characterized by single crystal/powder XRD, UV?vis?IR absorption, FTIR, thermal analysis and powder SHG measurements have been studied. The grown crystals were thermally stable up to 137.53 °C. The GBNPN crystal exhibits second harmonic generation efficiency of about 1.35 times than that of potassium di hydrogen phosphate (KDP). Mechanical properties such as micro hardness (H_v) and Mayer's index, n, have been carried out by indentation method. The refractive index (μ) has been measured by the Brewster's angle method.     

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.     

Synthesis,growth and physicochemical properties of an organometallic nonlinear optical crystal: Mercury cadmium chloride thiocyanate

SCN⁻ ligand based organometallic non-linear optical mercury cadmium chloride thiocyanate (MCCTC) crystals are grown from water plus methanol mixed solvent by slow evaporation technique. The grown crystals are confirmed by single crystal X-ray diffraction analysis. MCCTC exhibits a SHG efficiency which is nearly 17 times more than that of KDP. The dielectric constant, dielectric loss and ac conductivity measurements of the sample have been carried out for different frequencies (100 Hz to 5 MHz) and, temperatures (308–388 K) and the results are discussed. Photoconductivity study confirms that the title compound possesses negative photoconducting nature. The surface morphology of MCCTC was also investigated.     

Enhanced non-linear optical response in hybrid GSPN crystals: Structural, optical and dielectric analysis

Transparent and well defined crystals of GSPN series have been grown with alpha-glycine in simultaneous presence of two nitrates (NaNO₃ and KNO₃). Transparent and well defined crystals (22 mm × 13 mm × 5 mm) have been obtained in 3-4 weeks time by slow cooling. Addition of a strong acid (0.5% HCl) during growth is seen to enhance solubility, SHG efficiency by 2.78 times, Meyer's hardness index by 1.7 times and M.P by 42 °C of that of GSPN crystals. The SHG efficiency of acid added-GSPN has been found to be more than that of KDP crystal. GSPN is found to crystallize in orthorhombic symmetry and the presence of chemical components/groups has been identified by CHNS, EDAX and NMR analysis. Comparative FTIR and Laser Raman analysis shows the presence of active peaks indicating the molecule with a lack of center of symmetry. The UV spectrum shows existence of wide transparency window suitable for optoelectronic applications with band gap energy of about 5.72 eV. The crystals exhibit linear I-V characteristic followed by switching at 41 V/cm. The dielectric loss was seen to decrease exponentially with applied frequency from 100 Hz to 1 MHz.     

Growth and optical property of ZnWO4: Er crystal

Good quality crystals ZnWO₄ activated with Er³⁺ have been grown by means of Czochralski method and characterized using optical spectroscopy techniques. XRD, absorption spectra, fluorescence spectrum are presented and the Judd-Ofelt intensity parameters Ω₂, Ω₄, and Ω₆ are obtained to be 6.76×10^-20, 0.37×10^-20, and 0.50×10^-20 cm², respectively. Along crystallographic axes, refractive indices are presented. The fluorescence decay time of the ⁴I_13/2 level has also been investigated and shows an exponential behavior with a lifetime value of 5.52 ms. The crystal is potentially used for green and infrared eye-safe lasers.     

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.