Organic nonlinear optical crystal 4-hydroxy-N-methyl 4-stilbazolium besylate synthesis and characterization

Novel organic nonlinear optical material 4-hydroxy-N-methyl 4-stilbazolium besylate has been synthesized and 7 mm × 5 mm × 3 mm size crystals were grown by slow evaporation technique. Single crystal X-ray diffraction analysis reveals that the crystal lattice is monoclinic. From powder X-ray diffraction analysis the diffraction planes have been indexed. Fourier transform infrared spectrum for our sample confirms the presence of functional groups in the grown crystal. Second harmonic efficiency was determined using Kurtz powder method in comparison with urea to confirm the nonlinearity of the material. The results are discussed in detail.     

Growth and characterization of l-phenylalanine nitric acid, a new organic nonlinear optical material

A new organic nonlinear optical material L-phenylalanine nitric acid [2C₉H₁₁NO₂.H⁺. NO₃⁻] (LPN), was synthesized in mixed solvent of deionised water and methanol and single crystals of LPN was grown by slow evaporation method. Transparent crystals upto 2.9 × 0.3 × 0.05 cm³ were obtained. The grown crystals have been subjected to powder X-ray diffraction studies to identify the crystalline nature. Single crystal X-ray diffractometer was utilized to measure unit cell parameters and to confirm the crystal structure. The modes of vibration of different molecular groups present in LPN were identified by FTIR spectral analysis. Transmission spectra reveals that the crystal has low UV cutoff of 295 nm and has a good transmittance in the entire visible region enabling its use in optical applications. Thermal properties of the crystals have been investigated using thermogravimetric (TG) and differential thermal analyses (DTA), which indicate that the material does not decompose before melting. The existence of second harmonic generation signals was observed using Nd:YAG laser with fundamental wavelength of 1064 nm.     

Growth and properties of UV nonlinear optical crystal ZnCd(SCN)4

A second-order nonlinear optical coordination crystal, zinc cadmium thiocyanate, ZnCd(SCN)₄ (ZCTC) was grown as a frequency doubler, emitting UV light. A large typical single crystal with dimensions up to 15×7×7 mm³ has been obtained by slow solvent-evaporation method for the first time. The infrared (IR) spectroscopy and X-ray powder diffraction (XRPD) of single crystals were performed at room temperature. The specific heat of the crystal has been measured to be 367.9 J/mol K at 300 K. The thermal expansion coefficients a- and c-oriented, have been measured to be −1.69×10⁻⁵ and 1.95×10⁻⁴ K⁻¹, respectively. The second harmonic generation (SHG) efficiency of ZCTC crystal is 51.6 times as high as that of urea reference, and the measured transmittance spectra from 190 to 3200 nm showed that the UV transparency cutoff occurs at 290 nm and the transmission is 73.22% at 380 nm. UV laser light of wavelength 380 nm has been achieved by the frequency doubling of a 760 nm laser diode at room temperature.     

Synthesis, structure, growth and physical properties of a novel organic NLO crystal: 1,3-Dimethylurea dimethylammonium picrate

A novel noncentrosymmetric crystal was prepared from 1,3-dimethylurea dimethylammonium picrate, C₁₁H₁₈N₆O₈ (DMUP), which was designed for second harmonic generation. DMUP crystals exist in noncentro symmetric space group Cmc2₁ with unit cell dimensions a = 14.288(4) Å, b = 17.023(5) Å, c = 6.8268(13) Å, α = β = γ = 90° and volume = 1660.5(8) Å³. The crystal structure of DMUP has been determined using single crystal X-ray diffraction studies. The single crystals of DMUP were successfully grown by the slow evaporation method with dimensions 10 mm × 4 mm × 3 mm using dimethylformamide as solvent. The structural perfection of the grown crystals has been analysed by High-resolution X-ray diffraction (HRXRD) rocking curve measurements. Powder test with Neodymium-doped Yttrium aluminum garnet (Nd:YAG) laser radiation shows a high second harmonic generation (SHG). The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser.     

Physicochemical properties and theoretical explanation of ZnCd(SCN)4 crystal

The crystal density and Mohs hardness of zinc cadmium thiocyanate (ZCTC), ZnCd(SCN)₄ have been measured at room temperature. The specific heat of the crystal is 699.5 J mol⁻¹ K⁻¹ at 300 K. The thermal expansion coefficient (TEC) along the a and c axes, respectively, is interpreted on the basis of crystal structure. The thermal decomposition process is characterized by thermogravimetry analysis and differential scanning calorimetry (TGA/DSC). The intermediates and final products of the thermal decomposition were identified by X-ray powder diffraction at room temperature. The high-temperature effect in air on the optical transmission of the crystal was also studied.     

Crystal growth and characterization of CuI single crystals by solvent evaporation technique

Cuprous iodide (CuI) crystals are grown by slow evaporation technique in three different solvents. Large CuI single crystals with dimensions of 7.5 mm × 5 mm × 3 mm are obtained in pure acetonitrile solvent at 40 °C. The as-grown crystals are analyzed by X-ray diffraction, energy-dispersive X-ray analysis, differential scanning calorimetry, current-voltage characteristic and photoluminescence spectrum. The results show that the CuI crystal has the zinc-blende structure with no secondary phase. The elemental Cu/I ratio is 1.09:1. The melting point of the crystal is 875 K and two phase transitions occur from room temperature to its melting point. The electrical conductivity of CuI platelet crystal is in the range of 1.11-2.38 Ω⁻¹ cm⁻¹. Under ultraviolet excitation, the CuI crystals exhibit three emission bands with peak positions at 426, 529 and 671 nm. The nature of the luminescence is discussed.     

Study of optimum growth condition and characterization of zinc mercury thiocyanate (ZMTC) single crystals in silica gel

Some bimetallic thiocyanate complexes exhibit excellent nonlinear optical properties. Single crystals of one such material, zinc mercury thiocyanate ZnHg(SCN)₄ have been grown in silica gel with gel technique by the process of diffusions and the optimum growth condition has been studied. Crystals of 4 mm length have been obtained. Their structural, optical and thermal properties have been studied. Structural analysis was carried out using an X-ray diffractometer and the crystal structure was confirmed to be tetragonal. Fourier transform infrared spectrum was obtained to confirm the functional groups. Transmission spectrum has been recorded in the solution state and the cut-off wavelength has been determined. Thermal stability of the grown crystal has been investigated by thermogravimetric and differential thermal analyses. Nonlinear optical property of the crystal has been confirmed using the Kurtz powder technique and a study of its second harmonic generation efficiency in comparison with urea has been made.     

Growth and characterization of l-asparagine thiourea monohydrate (LATM): A nonlinear optical single crystal

l-Asparagine thiourea monohydrate (LATM) single crystal has been successfully grown (size 15 × 10 × 3 mm³) by slow evaporation solution growth technique. To the best of our knowledge this is the first report to the literature. The grown crystal was characterized by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopic analysis. The UV-Vis transmittance spectrum shows that the material has wide optical transparency in the entire visible region. The relative second harmonic generation was confirmed by Kurtz powder technique. The mechanical properties have been studied using Vickers microhardness tester. The birefringence of the crystal was measured in the visible region and it was found to vary with the wavelength.     

Growth and spectral properties of Er:NaGd(WO4)2 crystal

A high optical quality Er³⁺-doped NaGd(WO₄)₂ single crystal with dimensions of ∅18 × 50 mm³ has been grown using the Czochralski method. The structure of the grown crystal was proved by X-ray powder diffraction. The accurate concentration of Er³⁺ ion in the crystal was measured. The absorption spectra, fluorescence spectra and fluorescence lifetime of the crystal were measured at room temperature. Green up-conversion luminescence has been observed when the crystal is excited at 965 nm.     

Crystal growth of Nd: NaLu(WO4)2

Nd: NaLu(WO₄)₂ single crystals have been grown by the top seeded solution growth (TSSG) method. The peaks shown in the X-ray powder diffraction pattern were assigned. The crystal belongs to the space group of I4₁/a and the unit-cell parameters were calculated as a = b = 5.168 Å, c = 11.174 Å, V = 298.46 Å³. It is a tetragonal scheelite-like single crystal. The DSC (differential scanning calorimeter) curve proved that the as-grown crystal had a glass transition at the temperature range of 733.8 °C-781.4 °C which was lower than its melting point at 1149.3 °C. The absorption and fluorescence spectra were measured at room temperature.     

Crystal growth and structure refinement of monoclinic Li2TiO3

Colorless platelet crystals of monoclinic Li₂TiO₃ with a maximum size of 5.0 mm × 5.0 mm × 0.5 mm were successfully grown by a flux method at 1373 K using a LiBO₂-Li₂O system flux. The stoichiometric chemical composition of Li₂TiO₃ was determined by the SEM-EDX, ICP-AES and density measurement using the single crystal samples. The thermal conductivity of the Li₂TiO₃ single crystals was evaluated using hot-disk method. A single-crystal X-ray diffraction study confirmed the monoclinic Li₂SnO₃-type structure, space group C2/c and the lattice parameters of a = 5.0623(5) Å, b = 8.7876(9) Å, c = 9.7533(15) Å, β = 100.212(11)°, and V = 427.01(9) Å³. The crystal structure was refined to the conventional values of R = 2.4% and wR=3.3% for 2187 independent observed reflections. The cationic arrangement of (LiTi₂) layers in Li₂TiO₃ was precisely revealed by the structure analysis.     

Crystal growth and spectral properties of Pr:La2(WO4)3

Pr³⁺-doped La₂(WO₄)₃ single crystal with dimensions up to Ø 20 mm × 35 mm has been grown by the Czochralski method. The structure of the Pr³⁺:La₂(WO₄)₃ crystal was determined by the X-ray powder diffraction and the Pr³⁺ concentration in this crystal was determined. The absorption and fluorescence spectra of Pr³⁺:La₂(WO₄)₃ crystal were measured at room temperature, and the fluorescence lifetime of main emission multiplets were estimated from the recorded decay curves. The spectral properties related to laser performance of the crystal were evaluated.     

Growth, thermal, dielectric and mechanical studies of triglycine zinc chloride, a semiorganic nonlinear optical material

Triglycine zinc chloride, a semiorganic material, has been grown by slow solvent evaporation technique from a mixture of aqueous solution of glycine and zinc chloride in 2:1 molar ratio at room temperature. The grown crystal is up to the dimension of 45 × 23 × 18 mm³. Characterization of the crystals was made using single-crystal X-ray diffraction for obtaining unit cell parameters. Powder X-ray diffraction was recorded and the major peaks were indexed. Simultaneous thermogravimetric analysis and differential thermal analysis were carried out for the as grown crystals to determine the thermal stability of the crystal. The crystals were further characterized by UV-Vis-NIR transmission spectrum in the range of 200 to 1100 nm. Dielectric constant and dielectric loss measurements were carried out at different temperatures and frequencies. Mechanical studies were carried out on the as grown crystal.     

Synthesis,crystal growth,structural, spectral,thermal, mechanical,linear and nonlinear optical studies of organic single crystal 4-Iodo 4-nitrostilbene (IONS): A potential NLO material

An organic nonlinear optical material 4-Iodo 4-nitrostilbene (IONS) has been synthesized and good optical quality single crystal was grown from ethyl methyl ketone solvent by the solution growth technique. Single and powder X-ray diffraction analyses reveals that the grown crystal belongs to monoclinic crystal system with noncentrosymmetric space group ‘P2₁’ and it has good crystalline nature. Functional groups and molecular structure of the title compound were confirmed by FTIR and ¹H NMR respectively. The UV–Vis–NIR absorption study reveals no absorption in the visible region and the cut-off wavelength was found to be at 412.84 nm, TG/DTA, mass spectral analysis, photoluminescence and microhardness studies have been carried out for the grown crystals and results are discussed in detail. The second harmonic efficiency of the IONS was determined by Kurtz–Perry powder technique which reveals that the IONS crystal (3.1 V) has greater efficiency i.e., 143 times to that of KDP (21.7 mV).     

Growth,microhardness, dielectric and photoconductivity studies on NPNaLi: A promising crystal for NLO applications

Single crystals of nonlinear optical sodium substituted lithium p-nitrophenolate trihydrate (NPNaLi·3H₂O) have been grown successfully by slow solvent evaporation technique. The grown crystals are subjected to powder X-ray diffraction, microhardness, dielectric and photoconductivity studies. NLO activity of the crystal is found to be increased in the presence of sodium ions. Microhardness on (1 1 0) and (1 0 1) planes reveal the anisotropic behaviour in Vicker's hardness number. Dielectric constant is found to be less and independent at higher frequencies. Electrical conductivity and photoconductivity are found to be increasing in the presence of sodium in the lattice of NPLi. The results of SEM analysis also have been revealed.     

Synthesis, growth, and characterization of nonlinear optical material l-arginine iodate crystal

Single crystals of nonlinear optical l-arginine iodate (l-Arg·2HIO₃) (C₆H₁₄N₄O₂·2HIO₃), were successfully grown for the first time by the temperature-lowering method and also by the slow evaporation method at a constant temperature (30 °C) from its aqueous solution at pH value of 6. Crystals were of average dimensions 3 × 2.5 × 1.0 cm³ by optimizing the growth parameters. Initially, solubility studies were carried out for four different solvents such as water, water-methanol, water-ethanol, and water-acetone. Among the four solvents, the solubility of l-Arg·2HIO₃ was found to be the highest in water and hence crystallization of l-Arg·2HIO₃ was carried out from aqueous solution. Morphology studies reveal that the crystals grow with reasonable growth rate along the [100], [001], [110¯] and [011] direction. As-grown crystals were characterized by density measurement, X-ray powder diffraction studies, infrared spectrophotometer, UV-Vis spectrometer, laser induced damage threshold studies and nonlinear optical study.     

Growth, thermal and mechanical properties of new nonlinear optical barium bis-paranitrophenolate paranitrophenol tetrahydrate single crystal

Barium bis paranitrophenolate paranitrophenol tetrahydrate, a new semiorganic nonlinear optical single crystal has been grown by slow evaporation solution growth technique at room temperature of 30 °C. Crystal of dimensions of 29 mm × 11 mm × 5 mm was obtained in a period of 30 days. X-ray diffraction analysis reveal the newness of the crystal structure belonging to the orthorhombic class with lattice parameters a = 19.899(5) Å, b = 28.019(8) Å, c = 10.745(4) Å and α = β = γ = 90°. The grown crystal is examined for its nonlinear optical nature with Kurtz powder technique after being sieved for particle sizes between 5 and 100 μm and analyzed for its thermal and mechanical properties. The effective nonlinear optical coefficient being 16 times greater than that of KDP crystal, good thermal stability up to 120 °C with the Meyer's constant n < 2 helps fashion the crystal towards device geometry.     

Single crystal growth and structure refinements of CsMxTe2−xO6 (M = Al, Ga, Ge, In) pyrochlores

Single crystals of CsM_xTe_2−xO₆ pyrochlores with M = Al, Ga, Ge, and In have been grown from a TeO₂ flux. Structure refinements from single crystal X-ray diffraction data are reported. These results are used to discuss deviations from ideal stoichiometry that result in electronic conductivity presumably related to mixed valency of tellurium.     

Growth and characterization of a new semi-organic nonlinear optical sodium paranitrophenolate paranitrophenol dihydrate single crystal

A new semi-organic nonlinear optical sodium paranitrophenolate paranitrophenol dihydrate single crystal is grown successfully using methanol as solvent by slow evaporation technique to dimensions of 14 × 5 × 4 mm³ in a period of 7 days. The grown crystal is characterized by X-ray diffractometry and UV-Visible spectral analysis. X-ray diffraction data reveals that the crystal belongs to monoclinic system with space group C2. Optical absorption studies illustrate low absorption in the entire UV and Visible region. The second harmonic generation (SHG) efficiency of the crystal measured by Kurtz's powder technique infers that the crystal has NLO coefficient 5 times greater than that of KDP crystal. Remarkable mechanical strength with the work hardening coefficient less than 2 and thermal stability up to 120 °C of the grown crystal is reported.     

Crystal growth, thermal and optical studies of semiorganic nonlinear optical material: l-lysine hydrochloride dihydrate

Single crystals of l-lysine hydrochloride dihydrate (LLHCD), a nonlinear optical material, have been grown by slow cooling technique from its aqueous solution. LLHCD was found to be highly soluble in water. The grown crystals have been subjected to single crystal X-ray diffraction to confirm the structure and to estimate the lattice parameters. The vibrational structure of the molecule is elucidated from FTIR spectra. Thermal analysis revealed the thermal stability of the grown crystals. The optical transmittance spectrum shows that the material possesses good optical transparency in the entire visible region with a UV cut-off wavelength at 228 nm. The mechanical properties of the grown crystal have been studied using Vicker's microhardness test. The laser damage threshold of 52.25 MW/cm² has been measured by irradiating Q-switched Nd:YAG laser (1064 nm).