Growth, structural, spectral, mechanical and dielectric characterization of RbCl-doped l-alanine hydrogen chloride monohydrate single crystals

Pure (undoped) and RbCl-doped LAHC single crystals were grown successfully by the solution method with the slow evaporation technique at room temperature. The grown crystals were colourless and transparent. The solubility of the grown samples were found out at various temperatures. The lattice parameters of the grown crystals were determined by the single crystal X-ray diffraction technique and the diffracting planes were indentified by recording the powder X-ray diffraction pattern. UV-visible transmittance studies were carried out for the grown samples. Chemical analysis and atomic absorption studies indicate the presence of rubidium in the doped LAHC crystals. Nonlinear optical studies reveal that the SHG efficiency increases when the LAHC crystal is doped with rubidium chloride (RbCl). From microhardness studies, it is observed that the RbCl-doped LAHC crystal is harder than the pure sample. It is observed that the dielectric properties of the LAHC crystal are altered when it is doped with rubidium chloride.     

Influence of l-alanine doping on crystalline perfection, SHG efficiency, optical and mechanical properties of KDP single crystals

Pure and l-alanine (LA) doped single crystals of potassium dihydrogen orthophosphate (KDP) were grown by slow evaporation solution technique (SEST) in aqueous solution at ambient temperature. Powder X-ray diffraction study was done to confirm the crystal system and lattice parameters of KDP. No additional phases were observed at all doping concentrations (1-7.5 mol%), which was further confirmed by FT-Raman spectroscopy analysis. The influence of LA doping on the crystalline perfection was assessed by high-resolution X-ray diffractometry (HRXRD) analysis. HRXRD studies revealed that the grown crystals could accommodate LA at the interstitial positions in the crystalline matrix of KDP up to some critical concentration without any deterioration in the crystalline perfection. Above this concentration, very low angle structural grain boundaries were developed and it seems that the excess LA above the critical concentration was segregated along the grain boundaries. The SHG efficiency was measured using the Kurtz powder technique. The relative SHG efficiency of the crystals was found to be increased with doping concentration up to 5 mol% and above this it decreases. Optical transmission study also revealed the same behavior with enhancement up to 5 mol% concentration and later decreased. The hardness values were found to be increased by increasing the doping concentration.     

Pressure-induced phase transformations in l-alanine crystals

Raman scattering and synchrotron X-ray diffraction have been used to investigate the high-pressure behavior of l-alanine. This study has confirmed a structural phase transition observed by Raman scattering at 2.3 GPa and identified it as a change from orthorhombic to tetragonal structure. Another phase transformation from tetragonal to monoclinic structure has been observed at about 9 GPa. From the equation of state, the zero-pressure bulk modulus and its pressure derivative have been determined as (31.5±1.4) GPa and 4.4±0.4, respectively.     

Studies on growth and characterization of l-alanine strontium chloride trihydrate single crystals for optical applications

The optically transparent nonlinear optical single crystals of l-alanine strontium chloride trihydrate (LASCT) were grown by slow evaporation solution growth method using water as solvent. The purity of the crystals was increased by the method of recrystallization. The grown crystals were analyzed by the single crystal X-ray diffraction pattern which proved that LASCT belongs to monoclinic crystal system. The presence of various functional groups and modes of vibrations were identified by FTIR spectroscopy. The optical absorption study confirms the suitability of the crystal for device applications. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA analyses. The dielectric constant and dielectric loss measurements of the grown crystals at different frequencies of the applied field were measured and reported. The mechanical strength of the crystal is estimated by Vicker's hardness test. The nonlinear optical properties of the grown crystals were confirmed by second harmonic generation test which shows the suitability of NLO applications.     

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 metal ions doped l-serine NLO single crystals for optoelectronic applications

Single crystals of pure and metal ions (K⁺, Na⁺ and Li⁺) doped l-serine have been grown by slow evaporation solution growth technique (SEST). Energy dispersive X-ray analysis (EDAX) and inductively coupled plasma optical emission spectroscopy (ICP-OES) prove the incorporation of metal ions into the doped crystals. The lattice parameters have been obtained from single crystal X-ray diffraction (XRD) studies. The presence of functional groups is identified by Fourier transform infrared (FTIR) and FT-RAMAN analyses. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) reveal that the thermal stability of lithium doped l-serine crystal is enhanced. The mechanical properties have been studied by vicker's microhardness test. UV–vis-NIR spectroscopy shows that the percentage of transmission is increased in lithium doped l-serine crystals. Potassium and lithium ions doped l-serine crystals have enhanced second harmonic generation (SHG) efficiency indicating that these crystals are potential candidates for non linear optical (NLO) applications.     

Unidirectional growth of l-lysine l-lysinium dichloride nitrate (l-LLDN) single crystals by the SR method

Bulk semi-organic single crystals of l-lysine l-lysinium dichloride nitrate (l-LLDN) were grown by Sankaranarayanan-Ramasamy (SR) method. The experimental parameters involved in the present work are discussed in detail. The cut-off wavelength and the transmittance of the crystal were determined by UV-vis-NIR spectral analysis. Mechanical stability of the crystal was determined by Vickers microhardness tester. Refractive index of the crystal was measured using Brewster’s angle method. A simple interferometric technique was used for measuring birefringence of the crystal. The frequency dependent dielectric constant (ε_r) and dielectric loss (tan δ) were also measured. The results were analyzed for the l-LLDN crystals grown by both conventional and unidirectional methods.     

Synthesis,growth and characterization of l-asparagine cadmium bromide: A novel semiorganic nonlinear optical single crystal

Single crystal of l-asparagine cadmium bromide (LACB), a semiorganic nonlinear optical material was grown by solution growth method at the room temperature. 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 was belongs to orthorhombic system. The UV–vis–NIR spectroscopic study revealed that the crystal has good optical transparency and lower cut off wavelength was found to be 230 nm. The presence of functional group was identified by Fourier transform infrared (FTIR) analysis. The chemical composition was confirmed by elemental analysis. The mechanical strength was studied and found to be 100 g by using Vicker's micro hardness tester. The thermal stability was found to be 218 °C by using TGA and DTA analysis. The second harmonic generation efficiency was carried out by using Kurtz–Perry powder technique and it was found to be 3.4 times higher than KDP 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.     

Characterization studies on the additives mixed l-arginine phosphate monohydrate (LAP) crystals

l-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na₂SO₃) mixed LAP (LAP:Na₂SO₃) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.     

Growth and characterization of pure and doped organic nonlinear optical single crystal: l-Alanine alaninium nitrate (LAAN)

The pure l-alanine alaninium nitrate (LAAN) single crystals and LAAN crystals doped with lanthanum oxide (La₂O₃), sodium chloride (NaCl), urea (CH₄N₂O), glycine (C₂H₅NO₂) and thiourea (CH₄N₂S) were grown by slow evaporation method. The X-ray diffraction analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDAX) analysis, UV–vis spectral analysis, dielectric studies and powder SHG measurement are studied systematically. The slight changes in the lattice parameters were observed for the doped crystals compared to pure LAAN crystal. The incorporation of doping into the crystal lattice was confirmed by energy dispersive X-ray analysis. There is no change in the transmission window due to doping and the percentage of transmission in doped samples was found to increase as compared to that of pure LAAN crystal. The dielectric constant of pure crystal was found to be less than that of doped crystals. The AC conductivity was found to increase after doping and with the increase in temperature. A green radiation of 532 nm was observed from the pure and doped LAAN crystals confirming the second harmonic generation (SHG) of the crystals.     

Linear and nonlinear optical properties of a new organic NLO l-asparaginium l-tartarate (AST) single crystal

A new organic NLO material l-asparaginium l-tartarate (AST) was synthesized and good quality crystals were grown from aqueous solution. The solubility and metastable zone width for AST solution were determined. Single crystal X-ray diffraction and powder X-ray diffraction analyses were carried out to confirm structure and crystalline nature of AST crystal. Optical transmittance and second harmonic generation efficiency (SHG) of the grown crystal were studied by UV?vis?NIR spectrum and Kurtz powder technique respectively. The transmittance of AST crystal was used to calculate the refractive index (n), the extinction coefficient (k) and reflectance (R). The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser.     

Growth and characterization of a pure and doped nonlinear optical l-histidine acetate single crystals

Single crystals of pure, Cu²⁺and Mg²⁺ doped l-histidine acetate (LHA) were grown successfully by slow evaporation technique. The X-ray diffraction (XRD) studies were carried out for the pure and doped grown crystals. Absorption of these grown crystals was analyzed using UV-vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 nm to 1500 nm. The pure and doped crystals are characterized by Fourier transform Raman (FT-Raman), thermal and photoconductivity studies. Vickers microhardness tests were carried out for the pure and doped crystals and the mechanical strengths were found. The dielectric constant and the dielectric loss with frequency were also studied.     

Synthesis, growth and characterization of l-valine cadmium chloride monohydrate—A novel semiorganic nonlinear optical crystal

Single crystals of l-valine cadmium chloride monohydrate (LVCC), a novel semiorganic nonlinear optical material were synthesized and grown from aqueous solution by slow evaporation method at room temperature. The powder X-ray diffraction pattern and FT IR spectrum analysis confirmed the formation of the new crystal. LVCC has good optical transmission in the entire visible region, which is an essential requirement for a nonlinear crystal. The thermal studies reveal that the material has good thermal stability. The LVCC crystal was characterized by energy dispersive X-ray analysis. The optical second harmonic generation conversion efficiency of LVCC was determined using Kurtz powder technique.     

Nucleation kinetics,growth and hardness parameters of l-alanine alaninium picrate (LAAP) single crystals

Amino acids are considered to be the building blocks of proteins and are gaining importance due to their interesting optical behavior. l-alanine is an amino acid which dissolves in water and it can react with other acids to form new compounds. In this work, l-alanine is mixed with picric acid to prepare l-alanine alaninium picrate (LAAP) salt. Solubility and metastable zone width were measured for LAAP salt and induction period was measured at different supersaturation ratios. The critical nucleation parameters were evaluated based on the classical theory of homogeneous nucleation. Using the optimized nucleation parameters, single crystals of LAAP salt were grown by slow evaporation technique. XRD and FTIR studies were carried out to understand structural and molecular formation of the crystal. Microhardness measurements were performed on the grown LAAP crystal and various parameters such as work hardening constant, stiffness constant, yield strength, resistance pressure and corrected hardness were evaluated. Nonlinear optical behavior of the sample was analyzed.     

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,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.     

Investigation on the growth,optical and thermal studies of a novel organic nonlinear optical crystal: l-Threonine diformate (LTDF)

l-Threonine diformate (LTDF), a novel organic nonlinear optical crystal has been synthesized and grown by slow evaporation technique. The grown crystals were subjected to single crystal and powder X-ray diffraction studies. Functional groups present in the material were identified by FT IR spectral analysis. Absorption spectrum shows that the crystal is found to be transparent in the visible region. Thermal analysis was performed to study the thermal stability of the crystal. The SHG efficiency of the grown crystal was confirmed by Kurtz–Perry powder technique.     

Studies on growth,structural, optical and mechanical properties of xylenol orange dye admixtured l-arginine phosphate single crystal

Bulk single crystals of pure and xylenol orange (XO) admixtured l-arginine phosphate (LAP) were grown by slow cooling technique. The cell parameters and crystallinity of pure and dye admixtured LAP crystals were confirmed by single crystal and powder X-ray diffraction analyses. HRXRD analysis reveals the presence of xylenol orange dye in interstitial site of LAP crystal lattice and it confirms the crystalline perfection of grown crystals. The functional groups of grown crystals were confirmed by FTIR spectral analysis. UV–vis transmission studies show the characteristic absorption of xylenol orange admixtured LAP crystal. Vickers’ microhardness and laser damage threshold studies were carried out on these crystals. Kurtz and Perry powder test was conducted to measure the second harmonic generation efficiency of pure and dye admixtured LAP crystals.     

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.