Crystal growth,structure and spectroscopic studies of a novel organic single crystal: L‐lysine p‐nitrophenolate monohydrate (LLNP)

A novel organic crystal, L‐lysine p‐nitrophenolate monohydrate (LLNP) has been grown successfully from an aqueous solution by the slow cooling method. Transparent single crystal of dimensions 22 × 12 × 12 mm³ has been obtained. The single crystal X‐ray diffraction has shown that LLNP belongs to the orthorhombic crystallographic system with space group P2₁2₁2₁. The functional groups and vibrational frequencies of the crystal have been identified using IR and Raman spectra. The proton and carbon configurations have been confirmed through ¹H‐NMR and ¹³C‐NMR spectra analyses. The UV‐Vis‐NIR transmittance spectrum for LLNP crystal has been recorded in the range from 200 to 2500 nm. The second harmonic generation (SHG) intensity of LLNP has been measured by powder SHG method and found to be as 4.2 times as that of KDP. The thermal properties have been studied by using thermo gravimetric (TG) and differential thermal analysis (DTA).     

Growth and characterization of L‐prolinium tartrate – A new organic NLO material

Single crystals of L‐Prolinium tartrate (C₅H₁₀NO₂)⁺ (C₄H₅O₆)^‐, a new organic non‐linear optical material of size: 15 × 10 × 10 mm³ were grown using submerged seed solution growth method. Characterization of the crystals was made using single crystal X‐ray diffraction and density determination. Spectroscopic, thermal, optical and mechanical studies were carried out. These studies show that the crystals are thermally stable upto 161°C, transparent for the fundamental and second harmonic generation of Nd: YAG (λ = 1064 nm) laser and possess good mechanical strength. Second harmonic generation (SHG) conversion efficiency was investigated to explore the NLO characteristics of this material using Kurtz and Perry method and it was found that the SHG conversion efficiency is about 90% of that of the standard KDP crystals. Laser damage threshold study was also carried out. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of the nonlinear optical crystal: L‐arginine trifluoroacetate

Single crystal growth of the organic nonlinear optical crystal, L‐arginine trifluoroacetate (L‐Arg·CF₃COOH, abbreviated as LATF) is reported. Low temperature solution growth method is employed for the growth of bulk single crystals. The cell parameters are verified by single crystal diffraction. Fourier transform infrared (FT‐IR) and Fourier transform Raman analysis are used to confirm the presence of various functional groups in the grown crystal. The thermal properties of the grown crystals are studied by thermogravimetric analysis and differential scanning calorinetry analysis (TGA/DSC). Second harmonic generation (SHG) measurement confirms the NLO properties of the grown crystal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Nucleation kinetics and growth aspects of organic nonlinear optical L‐arginine trifluoroacetate single crystals

Experimental determination of solubility, metastable zonewidth and induction period for an organic nonlinear optical (NLO) L‐arginine trifluoroacetate (LATF) crystal is reported. The interfacial tension for different supersaturation conditions has been estimated for the LATF solution at 45°C. Bulk crystal of dimensions 57x5x3 mm³ has been grown by temperature lowering technique using optimized growth parameters. Powder X‐ray diffraction and FTIR studies confirm the crystalline nature and the functional groups of the grown crystals respectively. Linear optical property of the grown crystal has been studied by UV‐Vis spectrum. Thermal analyses have revealed that the compound is thermally stable upto 212°C. Kurtz powder SHG test confirm the nonlinear optical properties of the as‐grown LATF crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,growth and characterization of S‐benzyl isothiouronium chloride single crystals

S‐Benzyl isothiouronium chloride single crystals were grown at room temperature by slow evaporation solution growth technique. Single crystal X‐ray diffraction study has been carried out to find the crystal system and unit cell parameters. Various functional groups present in the grown material have been identified using FTIR spectra. The transparency of crystal was tested using UV‐visible spectra. The grown crystal exhibits second harmonic generation (SHG). TGA/DTA analysis also carried out. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Structural,thermal and optical characterizations of a NLO material: L‐alaninium oxalate

An organic electro‐optic and nonlinear optical (NLO) material, L‐alaninium oxalate, was synthesized by the standard method. The synthesized material was purified by repeated recrystallization. Single crystals were grown by the slow evaporation technique. The grown crystals were transparent and had optimum dimensions (20 × 3 × 2 mm³) and were characterized by single crystal XRD, FT‐NMR, FT‐IR, TGA‐DTA and UV‐Vis‐NIR techniques. The second harmonic generation (SHG) from the material was confirmed using Nd:YAG laser. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and characterization of a new nonlinear optical single crystal: L‐Lysinium trifluoroacetate

Single crystals of a new L‐Lysine salt: L‐Lysinium trifluoroacetate {abbreviated as LLyTFA; [(NH₂)‐(CH₂)₄‐CH‐(NH₃)‐(COOH)]⁺ CF₃COO^‐} were grown by slow evaporation of an aqueous solution at room temperature. The grown crystals were subjected to single crystal X‐ray diffraction, FTIR and UV‐Vis‐NIR spectrum analyses. The UV‐Vis‐NIR spectrum shows that the absorption is very less in the whole of the region from ultraviolet to near IR. The Kurtz‐Perry powder SHG measurement using a Nd:YAG laser of wavelength 1064nm confirms the frequency doubling of the crystal and its powder SHG efficiency was measured as d_eff = 0.96 d_eff (KDP). (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Single crystal growth,structural, optical,mechanical, dielectric and thermal studies of formic acid doped potassium dihydrogen phosphate crystal for NLO applications

Optically transparent formic acid (FA) doped potassium dihydrogen phosphate (KDP) crystal of dimension 21×15×9 mm³ has been grown by slow evaporation solution technique (SEST). The X‐ray diffraction (XRD) technique was used to confirm the cell parameters and the shifts in peak positions of identified reflecting planes. The incorporation of FA in KDP has been qualitatively analyzed by fourier transform infrared analysis. The UV‐visible absorption spectrum of crystals has been recorded in the range of 200 to 900 nm and the doped KDP crystal is found to have improved optical parameters than pure KDP. The color centered photoluminescence emission spectrum of grown crystal has been illustrated in visible region. The mechanical behavior of pure and doped KDP crystal has been investigated using the Vicker's microhardness analyzer and hardness parameters have been calculated. The effect of FA on thermal stability of KDP crystal was examined by means of thermogravimetric and differential thermal analysis. The temperature dependent dielectric behavior of crystals was studied.     

Growth and characterization of nonlinear optical zinc hydrogen phosphate single crystal grown in silica gel

Good optical quality single crystals of zinc hydrogen phosphate (ZnHPO₄) having dimensions up to 8×2×2 mm³ have been grown with the aid of sodium meta silicate gel. Single crystal XRD studies confirm that the crystal belongs to the orthorhombic system with space group P2₁2₁2₁. The functional groups present in the crystals were confirmed using FTIR technique. Optical absorbance shows very low absorption in the entire visible region. Differential thermal and thermo gravimetric analysis confirmed that the crystal is stable up to 193°C. Photoconductivity study reveals positive photoconductivity in the presence of photo active centers formed by trap energy levels. The NLO activity of the crystal was confirmed by Kurtz powder technique. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth of Inclusion Free KTP Crystals by Top Seeded Solution Growth and their Characterization

KTiOPO₄ single crystals of dimensions 34 × 15 × 15 mm³ have successfully been grown by Top Seeded Solution Growth (TSSG), using phosphate flux (K₆P₄O₁₃), employing a home made vertical cylindrical three zone resistive heated furnace. Growth experiments were carried out with <001> seed orientation. A method to grow inclusion free crystal with less dislocation density is proposed, by employing cooling rate of 0.5‐2 K/day and rotation rate of 60‐30 rpm. UV‐VIS transmission studies were performed and the dependence of absorption coefficient with wavelength is discussed. SHG elements of dimension 8 × 7.5 × 7.5 mm³ were fabricated and conversion efficiency of 58 % was achieved without antireflection coating. Nature of ionic conductivity and ferroelectric phase transition behavior of KTP crystals along the crystallographic polar axis in the frequency range of 100 Hz – 10 MHz are discussed.     

Growth and characterization of a new potential second harmonic generation material from the amino acid family: L‐Valinium picrate

L‐Valinium picrate (C₅H₁₂NO₂)⁺. (C₆H₂N₃O₇)^–, a non‐linear optical material from the amino acid family which has large second harmonic generation (SHG) efficiency, was grown by slow evaporation method. Characterization of the crystals was made using single crystal X‐ray diffraction. The functional groups and the modes of vibrations were found by using the Fourier transform infrared (FTIR) spectroscopy. The second harmonic generation (SHG) conversion efficiency was investigated using the Kurtz and Perry method. The SHG conversion efficiency is 60 times higher than that of the standard KDP and 8 times higher than that of the standard Urea and the optical transparency was analyzed using UV‐visible‐NIR absorption spectrum. The structural features of the material leading to the large SHG efficiency are discussed. Microhardness and dielectric studies were also carried out. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of a nonlinear optical crystal—2,6-diaminopyridinium 4-nitrophenolate 4-nitrophenol (DAPNP)

Bulk optical-quality single crystal of 2, 6-diaminopyridinium 4-nitrophenolate 4-nitrophenol (DAPNP) with dimensions of 22×15×8 mm³ was successfully grown by the controlled slow cooling solution growth method. Thermogravimetric (TG) and differential thermal analysis (DTA) were carried out to characterize the thermal behaviors of the grown crystals. Its specific heat was determined and dielectric properties from 298.15 to 353.2 K have also been investigated. Second-harmonic generation (SHG) on powder samples indicated that DAPNP is a phase-matchable material and its SHG coefficient is 11.5 times larger than that of urea.     

Structural,thermal, mechanical and z‐scan studies on 4‐nitrophenol single crystals

4‐nitrophenol (4‐NP) single crystals have been grown by using slow evaporation and slow cooling techniques. A single crystal with size in the range of 7x3.4x1.8cm³ has been obtained by slow cooling method. The grown crystals have been subjected to various characterization studies. The powder XRD spectrum of 4‐NP reveals the good crystalline nature of the grown crystal. Single crystal XRD studies show that the crystal belongs to monoclinic system with cell parameters of a=6.09 Å, b=8.79 Å, c=11.61 Å, α=γ=90°, β=103.15°. The resultant FTIR spectrum confirms the various functional groups present in 4‐NP. Thermal analysis has been performed on the material to study the thermal stability of 4‐NP. The grown crystals belong to the category of soft materials as confirmed by Vickers Hardness tests. The optical transmiitance of 4‐NP single crystals has been measured from Vis‐IR spectroscopy study. The nonlinear optical properties have been analyzed by z‐scan technique and 4‐NP is found to be self defocusing because of its negative nonlinear refractive index. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of non‐linear optical crystal ZnCd(SCN)4

Single crystals of ZCTC with dimension up to 5x2x3mm³ were grown from aqueous solution by slow solvent evaporation method and the grown crystals were confirmed by single XRD and CHN analysis. The SHG efficiency of ZCTC was evaluated using Kurtz Perry technique. Its efficiency was found to be nearly 12 times that of urea when studied with the fundamental wavelength of 1064 nm. The mechanical properties of the grown crystal have been investigated by Vickers microhardness testing. The thermal parameters such as the thermal diffusivity (α), thermal effusivity (e), thermal conductivity (k) and heat capacity (c_p) of ZCTC were measured by an improved photopyroelectric (PPE) technique and the results were discussed. The TG/DTG studies reveal that the decomposition of the sample begins around 350°C. The photoconducting nature of ZCTC has also been investigated and reported. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of a novel NLO crystal bis-glycine hydrogen chloride (BGHC)

Single crystals of bis-glycine hydrogen chloride (BGHC), a semiorganic nonlinear optical (NLO) material, have been grown by slow solvent evaporation technique. Good optical quality single crystals with dimensions up to 33×5×5 mm³ are obtained. The crystals are characterized by optical transmission spectrum, FTIR and X-ray diffraction studies. The thermal stability of the crystal is studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The second harmonic generation (SHG) efficiency of BGHC was found to be 5.6 times that of KDP. The laser damage threshold values studied in single shot mode indicates that BGHC crystal possesses a fairly high value of 9.8 GW/cm² and thus the NLO studies confirmed the superiority of BGHC over KDP and urea crystals. The dielectric constant of the crystal was studied as a function of frequency and the results are discussed.     

Growth and characterization of bis-glycine sodium nitrate (BGSN), a novel semi-organic nonlinear optical crystal

Single crystals of bis-glycine sodium nitrate (BGSN), a semi-organic nonlinear optical (NLO) material, have been grown by slow cooling method. Good optical quality single crystals with dimensions up to 1.6×1.6×1.0 cm³ are obtained. Using a single-crystal diffractometer, the morphology of BGSN crystal was identified. Powder X-ray diffraction confirms the crystalline nature of BGSN. The grown crystals were characterized by optical transmission spectrum (UV) and FTIR studies. The NLO property of the crystal was confirmed by Kurtz second harmonic generation (SHG) test, and the output power generated by the crystal was compared with that of KDP. The thermal stability of the crystal was studied by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Micro hardness study was carried out for different planes, and the anisotropy behavior of the crystal was observed.     

Synthesis,growth and characterization of l‐alaninium oxalate ‐ a novel organic NLO crystal

Nonlinear optical material of L‐alaninium oxalate (LAO) has been synthesized and single crystals are grown by slow evaporation technique. The solubility data of LAO is determined in water. Single crystal X‐ray diffraction study showed that LAO belongs to orthorhombic system with a non‐centrosymmetric space‐group P2₁2₁2₁. The functional groups have been identified from FT‐IR spectrum. The UV‐Vis‐NIR spectrum of LAO shows less optical absorption in the entire visible region. The second harmonic generation (SHG) in the material was estimated using Nd:YAG laser. The mechanical properties of the grown crystals are studied using Vickers microhardness tester. The AC and DC conductivity, and dielectric studies are also carried out and reported for the first time. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal growth and magnetic properties of the copper coordination polymer [Cu(µ ‐C2O4)(4‐aminopyridine)2(H2O)]n

In this paper, we consider various ways of crystal growth of the polymer [Cu(µ ‐C₂O₄)(4‐aminopyridine)₂(H₂O)]_n. Single crystals of the size of 1.5×1.5×0.2 mm³ have been grown by a slow diffusion technique from solutions of the monoammine copper complex and of the mixture of potassium oxalate and aminopyridine with the stoichiometric ratio. Magnetic susceptibility and ESR measurements have been performed on single crystals large enough for investigating anisotropic properties. The susceptibility can be well described within the model of a Heisenberg antiferromagnetic spin chain. The magnetic measurements reveal a small concentration of paramagnetic moments reflecting the high quality of the single crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth and characterization of semiorganic NLO crystals of LAHClBr

Single crystals of non‐linear optical (NLO) LAHClBr were grown by slow evaporation technique from its aqueous solution. Good optical quality crystals having dimensions up to 12 × 9 × 7 mm³ were obtained. The lattice parameters and morphology for the grown crystals were determined using single crystal XRD. The crystals were characterized by FT‐Raman, optical absorption, thermal (DTA and TGA) and dielectric studies. LAHClBr was found to be thermally stable up to 124.3°C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Optical and dielectric studies on pure and Ni2+, Co2+ doped single crystals of bis thiourea cadmium chloride

Good quality single crystals of Ni²⁺, Co²⁺ ions doped Bisthiourea Cadmium Chloride (BTCC) are some of the excellent and efficient non‐linear optical materials grown from aqueous solution by slow evaporation method. The lattice parameters of the grown crystals are determined by single crystal X‐ray analysis. UV spectral analyses on these samples reveal the improved transparency of the doped crystals ascertaining the inclusion of metal ion in the lattice. FTIR spectral analysis carried out on the materials confirm the presence of functional groups. Dielectric measurements reveal that the dielectric constant of pure and doped crystals decreases with increase of frequency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)