Growth,optical, mechanical and electrical studies of nonlinear optical crystal: l-Valinium oxalate

l-Valinium oxalate (LVO) single crystal has been grown by solution growth technique at room temperature. The crystal structure and lattice parameters were determined for the grown crystal by single crystal X-ray diffraction studies. Optical constants like band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV–vis–NIR spectrum. The microhardness studies reveal the mechanical strength of the grown crystal. The dielectric constant, dielectric loss and AC conductivity of the compound were calculated at different temperatures and frequencies to analyze the electrical properties. Nonlinear optical property was discussed to confirm the SHG efficiency of the grown crystal.     

Growth and characterization of potassium halides mixed l-arginine phosphate monohydrate semi organic nonlinear optical single crystals

Single crystals of pure and potassium halides additive mixed l-arginine phosphate monohydrate have been grown with good optical quality by slow temperature reduction method. Microbial growth aspects and coloration have been studied on the growth solutions. In addition to that the structural properties have been studied by powder X-ray diffraction method and Fourier transform infrared spectral analyses for the grown crystals. Thermal stability of the grown crystals were studied by thermo gravimetric (TG) and differential thermal analyses (DTA) and found that the grown crystals are suitable for device fabrication for frequency conversion applications.     

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.     

Structural,optical, thermal and mechanical characterization of an organic nonlinear optical material: 4-methyl-3-nitrobenzoic acid single crystal

Organic single crystals of 4-methyl-3-nitrobenzoic acid (4M3N) have been grown by slow evaporation solution growth technique at room temperature. The single crystal X-ray diffraction study reveals that 4M3N crystallizes in monoclinic system with space group P21/n. The crystalline perfection of the crystal was analyzed by high resolution X-ray diffraction (HRXRD) measurements. The functional groups present in 4M3N have been identified from FT-IR and FT-Raman spectra. The lower cut-off wavelength of 4M3N is found to be 404 nm and the optical band gap is calculated as 2.91 eV. The refractive index shows normal behavior with wavelength. The physio chemical changes, decomposition and stability of the 4M3N compound were established by TG-DTA studies. Vickers microhardness measurement concludes that 4M3N belongs to soft material (n=2.5) category. The LDT value is found to be higher than that of KDP and some of the important organic NLO materials. The third order nonlinear refractive index and nonlinear absorption coefficient of the 4M3N have been measured by Z-scan studies. The imaginary and real parts of the third-order susceptibility values were determined as Im χ³=9.129×10⁻¹¹ esu and Re χ³=1.4034×10⁻⁹ esu respectively. The dislocation density was calculated to be 3.0448×10⁶ cm⁻² which indicates the quality of the crystal.     

Growth and characterization of a new organic nonlinear optical crystal: Vanillylideneaniline

Vanillylideneaniline with chemical formula C₁₄H₁₃NO₂ (VAN), a second order nonlinear optical (SONLO) organic single crystal was synthesized and grown for the first time from dimethyl formamide (DMF) employing slow solvent evaporation technique. Single crystal X-ray diffraction data reveals that the crystal belongs to noncentrosymmetric orthorhombic space group C222₁. The high-resolution diffraction curve containing single peak with full width at half maximum (FWHM) of 62 arc s ascertains VAN was perfectly crystallized and free from structural grain boundaries. The formation of the material was confirmed quantitatively by FTIR, ₁H¹ and ¹³C NMR spectral analyses. The UV–vis–NIR spectrum reveals the percentage of the transmission of VAN crystal in the entire region. The variations of dielectric constant (?_r) and dielectric loss (D) with frequency at different temperatures were investigated. The SHG of VAN crystal is confirmed by Kurtz Powder technique. The mechanical strength of the crystal was estimated by Vickers hardness test. VAN has yield strength of 8.70 MPa. Thus the grown organic VAN single crystal can be recommended as a promising candidate for SONLO application and device fabrication technology.     

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.     

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.     

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,optical and electrical studies of the nonlinear optical crystal: Glycine thiourea

Single crystals of the nonlinear optical material glycine thiourea were grown by the slow evaporation technique. The crystal structure and lattice parameters were determined for the grown crystal by the single crystal X-ray diffraction studies. Single crystal XRD revealed that the material crystallized in a monoclinic crystal system. Optical studies have been carried out and it was found that the tendency of transmission observed from the specimen with respect to the wavelength of light, is practically more suitable for opto-electronic applications. The dielectric constant, dielectric loss and ac conductivity of the compound were calculated at different temperatures and frequencies, to analyze the electrical properties. The photoconductive behavior of the material is also investigated and the results are discussed.     

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.     

Studies on optical,mechanical, dielectric properties of bisthiourea nickel bromide NLO single crystal

Bisthiourea nickel bromide (BTNB) single crystal has been grown by solution growth technique at room temperature. The crystal structure and lattice parameters were determined for the grown crystal by single crystal X-ray diffraction studies. Optical constants like band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV–vis-NIR spectrum. Nonlinear optical property was discussed to confirm the SHG efficiency of the grown crystal. The mechanical strength of the grown crystal was analyzed using Vickers microhardness tester. The dielectric constant and dielectric loss of bisthiourea nickel bromide are measured in the frequency range of 50 Hz to 5 MHz at different temperatures. The ac conductivity studies were carried out on bisthiourea nickel bromide crystals. In order to investigate the growth mechanism and surface features, etching studies are carried out for the crystal. Photoconductivity studies were carried out on bisthiourea nickel bromide crystals.     

Growth and characterization of an efficient nonlinear optical single crystal: Urea p-nitrophenol

An organic nonlinear optical single crystal of urea p-nitrophenol has been synthesized and grown by slow evaporation solution growth technique. The grown crystals were characterized by single crystal and powder X-ray diffraction analysis and it was found to be the structure of the crystal belongs to triclinic system. The various functional groups were identified by FT-IR and Raman spectral analysis. Thermal stability of the grown crystal was studied by TGA/DTA. The optical properties of the grown crystals were analyzed by UV–vis. The mechanical properties of the grown crystal were studied by Vickers microhardness measurements. Nonlinear optical property of the crystal was confirmed using the Kurtz and Perry powder technique and a study of its SHG efficiency in comparison with KDP has made.     

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.     

A correlative optical microscopy and scanning electron microscopy approach to locating nanoparticles in brain tumors

The growing use of nanoparticles in biomedical applications, including cancer diagnosis and treatment, demands the capability to exactly locate them within complex biological systems. In this work a correlative optical and scanning electron microscopy technique was developed to locate and observe multi-modal gold core nanoparticle accumulation in brain tumor models. Entire brain sections from mice containing orthotopic brain tumors injected intravenously with nanoparticles were imaged using both optical microscopy to identify the brain tumor, and scanning electron microscopy to identify the individual nanoparticles. Gold-based nanoparticles were readily identified in the scanning electron microscope using backscattered electron imaging as bright spots against a darker background. This information was then correlated to determine the exact location of the nanoparticles within the brain tissue. The nanoparticles were located only in areas that contained tumor cells, and not in the surrounding healthy brain tissue. This correlative technique provides a powerful method to relate the macro- and micro-scale features visible in light microscopy with the nanoscale features resolvable in scanning electron microscopy.     

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,crystal perfection,optical and electrical properties of organic crystal: Brucinium 5-sulfosalicylate trihydrate

Single crystals of brucinium 5-sulfosalicylate trihydrate (B5ST) were grown from ethanol–water (1:1) mixed solvent by slow evaporation method. Structure and crystallinity of the grown crystal were confirmed by single-crystal X-ray diffraction analysis. Presence of functional groups and coordination of brucine and 5-sulfosalicylic acid (5SSA) were confirmed by FT-IR and FT-Raman analyses. Optical transmittance spectrum shows the crystal having 90% transmittance in the visible region. The laser-induced surface damage threshold for the grown crystal was measured as 13.64 GW cm⁻² with Nd:YAG laser assembly. Dielectric study was performed on the single crystal to study the power dissipation of the material in the presence of alternating electric field. Crystal defects and surface morphology are studied by dissolution solvent technique and it reveals the layer growth mechanism for B5ST compound.     

Growth, optical and thermal studies on organic nonlinear optical crystal: 2-Furoic acid

2-Furoic acid (2FA), an organic third order nonlinear optical single crystal, has been synthesized and grown successfully by slow solvent evaporation technique. The space group and lattice parameters of the grown crystals were obtained by single crystal X-ray diffraction analysis. The presence of the functional groups was confirmed by Fourier Transform Infrared (FTIR) spectroscopy. Optical absorption studies reveal low absorption in the UV and visible regions and the UV cut-off wavelength is found to be at 240 nm. The thermal stability of the material examined by TGA analysis, reveals that the material is thermally stable up to 130 °C. The third order nonlinear optical parameters (nonlinear refractive index, nonlinear absorption coefficient and real and imaginary parts of the third order nonlinear optical susceptibility) were derived by Z-scan technique. This reveals that the crystal has a negative refractive index, which indicates the defocusing nature of the material.     

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.     

Structural stabilities, electronic, elastic and optical properties of SrTe under pressure: A first-principles study

The structural, electronic, elastic and optical properties as well as phase transition under pressure of SrTe have been systematically investigated by first-principles pesudopotential calculations. Five possible phases of SrTe have been considered. Our results show that SrTe undergoes a phase transition from NaCl-type (B1) to CsCl-type (B2) structure at 10.9 GPa with a volume collapse of 9.43%, and no further transition is found. We find that SrTe prefer h-MgO instead of wurtzite (B4) structure for its metastable phase because that the ionic compound prefers a high coordination. The elastic moduli, energy band structures, real and imaginary parts of the dielectric functions have been calculated for all considered phases, and we find that a smaller energy gap yields a larger high-frequency dielectric constant. Our calculated results are discussed and compared with the available experimental and theoretical data.     

Crystal growth and characterization of l-phenylalaninium trichloroacetate—A new organic nonlinear optical material

Amino acid based crystals exhibit excellent nonlinear and electro-optical properties. A new nonlinear optical single crystal l-phenylalaninium trichloroacetate (LPTCA) belonging to the amino acid group was grown by the slow evaporation solution growth method. The grown crystals have been subjected to powder X-ray diffraction studies to identify the crystalline nature. Single crystal X-ray diffraction study showed that LPTCA belongs to monoclinic crystal system. Fourier transform infrared study is used to confirm the presence of various functional groups in the grown crystal. Optical transparency of the grown crystals was investigated by UV-vis-NIR spectrum. The lower optical cutoff wavelength for this crystal is observed at 254 nm and energy band gap is 4.89 eV. Thermal properties of the LPTCA crystal were studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques, which indicate that the material does not decompose before melting. The melting point of grown crystal was observed to be 136 °C in a melting point apparatus. The existence of nonlinear optical (NLO) property of LPTCA was confirmed by second harmonic generation test using Nd:YAG laser fundamental wavelength of 1064 nm.