Growth and characterization of an organic nonlinear optical material: l-alanine alaninium nitrate

l-alanine alaninium nitrate (LAAN), an organic nonlinear optical material was grown by slow evaporation technique at room temperature from its aqueous solution at pH value of 2.5. As grown single crystals were characterized for its spectral, thermal, linear and second order nonlinear optical properties. LAAN crystallizes in monoclinic system with space group P₂₁ and cell parameters a = 7.846 Å, b = 5.431 Å, c = 12.806 Å and β = 94.65°. The mode of vibrations of different molecular groups present in LAAN were identified by FTIR studies. The thermal behaviour of the crystals has been investigated using thermogravimetry (TG) and differential thermal analysis (DTA), which indicates that the material does not decompose before melting. Transmittance spectrum reveals that the crystal has a low UV cut-off of 320 nm and has a good transmittance in the entire visible region. NLO property of the crystal was confirmed by Kurtz SHG powder technique.     

Studies on the nonlinear optical single crystal: Ammonium d,l-tartrate (C4H9NO6)

The organic nonlinear optical material ammonium d,l-tartrate single crystal has been successfully grown by slow evaporation solution technique (SEST). The grown crystals were characterized by single crystal XRD and the lattice parameters have been confirmed. The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction measurement. The optical transmittance spectrum shows that the material has a good optical transparency in the entire visible region with the UV cut-off wavelength at 234 nm. Thermogravimetric and differential scanning calorimetric measurements were performed to study the thermal properties of the grown crystal. Chemical etching studies were attempted to determine the dislocation density of the grown crystal. Mechanical behavior was assessed using Vickers hardness testing carried out on (0 0 1) crystallographic plane. The Kurtz–Perry powder SHG technique confirms the NLO property of the grown crystal and the efficiency of AMT crystal was found to be 1.3 times that of standard KDP crystal.     

Growth and characterization of 4-methyl benzene sulfonamide single crystals

Single crystals of 4-methyl benzene sulfonamide (4MBS) were successfully grown from aqueous solution by low temperature solution growth technique. The grown crystal was characterized by single crystal XRD and powder XRD methods to obtain the lattice parameters and the diffraction planes of the crystal. UV–vis–NIR absorption spectrum was used to measure the range of optical transmittance and optical band gap energy. The optical transmission range was measured as 250–1200 nm. FTIR spectral studies were carried out to identify the presence of functional groups in the grown crystal. The thermal behavior of the crystal was investigated from thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) study. The absence of SHG was noticed by Kurtz and Perry powder technique. The third order NLO behavior of the material was confirmed by measuring the nonlinear optical properties using Z-scan technique and it was found that the crystal is capable of exhibiting saturation absorption and self-defocusing performance.     

Crystal growth and structure of L-methionine L-methioninium hydrogen maleate—a new NLO material

A new organic nonlinear optical (NLO) crystal from the amino acid family, viz., L-methionine L-methioninium hydrogen maleate (LMMM), has been grown by slow evaporation method from aqueous solution. Bulk crystals were grown using submerged seed solution method. The structure was elucidated using the single crystal x-ray diffraction data. The compound crystallized in the space group P2₁ and the unit cell contains a protonated L-methioninium cation and a zwitterionic methionine residue plus a maleate anion. The backbone conformation angles Ψ¹ and Ψ² are in cis and trans configurations for both the methionine and methioninium residues, respectively. Amino and carboxyl groups of the methioninium and methionine residues are connected through N–H…O hydrogen bonds leading to a ring R₂²(10) motif.     

Synthesis,growth and characterization of π conjugated organic nonlinear optical chalcone derivative

A new potentially useful nonlinear optical organic material, 1-(5-chlorothiophen-2-yl)-3-(2,3-dimethoxyphenyl)prop-2-en-1-one, has been synthesized and grown as a high-quality single crystal by the slow evaporation technique. The grown crystals were characterized by FT-IR, NMR, thermal analysis, and UV–visible spectroscopy. The material is thermally stabile up to 111 °C. The mechanical property of the grown crystals was studied using Vickers microhardness tester and the load dependence hardness was observed. The third order nonlinear optical properties of the material such as real and imaginary part of χ⁽³⁾, nonlinear absorption coefficient and nonlinear refractive index were determined using nanosecond laser pulses at 532 nm wavelength by employing Z-scan technique. The nonlinear refractive index is found to be of the order of 10⁻¹¹ cm² W⁻¹. The magnitude of third order susceptibility is of the order of 10⁻¹³ esu. The observed increase in the third order nonlinearity in these molecules clearly indicates the electronic origin. The compounds exhibit good optical limiting at 532 nm. The best optical limiting behavior of this molecule is due to the substituted strong electron donor.     

Influence of Metallic Substitutions on the Optical and Mechanical Properties of NLO Benzoyl Glycine Crystals

Benzoyl glycine （BG） is a promising organic nonlinear optical （NLO） crystal, whose second harmonic generation （SHG） efficiency is much higher than that of KDP （potassium dihydrogen phosphate）. Single crystals of pure, Cu2＋ and Cd2＋ doped BG were grown by slow evaporation technique. Optically transparent and defect free single crystals of size up to 10 mm×15 mm×10 mm were harvested in a period of 40-60 days. The growth conditions of pure and doped crystals of BG were optimized and the grown crystals were confirmed by single crystal XRD （X-ray diffraction）. The grown crystals were characterized by FTIR （Fourier transform infrared spectroscopy）, optical absorption and microhardness studies. The microhardness studies confirm that BG has a moderate VHN （Vickers hardness number） value in comparison to the.other organic NLO crystals. The efficiency of frequency doubling was measured for the using Nd：YAG laser and the results were discussed.     

Structural,thermal, dielectric,nonlinear optical properties and DFT investigations of a novel material 2-(6-chloropyridin-3-yl)-N'-(2,3-dihydro-1,4-benzodioxin-6-ylmethylidene)acetohydrazide for optoelectronic applications

A new organic nonlinear optical (NLO) material 2-(6-chloropyridin-3-yl)-N'-(2,3-dihydro-1,4-benzodioxin-6-ylmethylidene)acetohydrazide (CDA) has been synthesized by reflux method. Single crystals were grown by slow evaporation technique and the crystal structure was elucidated by single crystal X-ray diffraction method. Density functional theory (DFT) calculations at B3LYP/6–31+?+?G(d, p) basis set was used to predict the molecular geometry and were carried out further to comprehend the electronic structure, vibrational spectra, natural bonding orbitals (NBO), frontier molecular orbitals (FMO) and molecular electrostatic potential (MEP). An optical transparency at the cut-off wavelength of 355 nm was determined by UV–Vis–NIR spectroscopy. Thermal behavior of CDA was studied by TGA/DTA analysis. The dielectric constant (ε), dielectric loss (tan δ) and AC conductivity as a function of frequency and temperature was studied. Second Harmonic Generation (SHG) efficiency of the CDA was determined using Kurtz and Perry powder technique and was 0.5 times greater than that of the KDP crystal. The third-order nonlinear optical properties were investigated in solution by Z-scan technique using a continuous wave (CW) DPSS laser at the wavelength of 532 nm. The title compound exhibited significant two-photon absorption (β?=?2.228?×?10–4 cm W^?1), nonlinear refraction (n₂?=?1.095?×?10–8 cm² W^?1) and optical limiting (OL threshold?=?2.511?×?103 W cm^?2) under the CW regime. The nonlinear optical parameters were calculated using time-dependent Hartree–Fock (TDHF) method. The overall obtained results suggested that the studied CDA molecule could be a potential NLO material for frequency generator, optical limiters and optical switching applications.

     

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.     

Growth and characterization of an organic nonlinear optical crystal: Glycinium trichloroacetate

Single crystal of glycinium trichloroacetate, an organic nonlinear optic (NLO) material, has been grown by slow solvent evaporation technique at room temperature. The grown crystal was subjected to single crystal X-ray diffraction for confirming the coordination formed, and the presence of various functional groups was studied by FTIR in the range 4000–450 cm⁻¹. UV–Visible transmittance studies were performed to analyze optical transparency of the crystal and second harmonic generation was investigated to explore the NLO property of the material. Thermogravimetric and differential thermal analysis have been performed to study thermal properties of the grown crystal. Dielectric constant and dielectric loss were studied at different temperatures and frequencies. Vicker's microhardness testing was carried out on the as grown crystal to reveal the mechanical properties of the crystal. Etching studies were made on the as grown crystal to analyze the structural imperfection of the crystal.     

Growth and characterization of benzaldehyde 4-nitro phenyl hydrazone (BPH) single crystal: A proficient second order nonlinear optical material

The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.     

Optical and dielectric properties of nitrophenolate based nonlinear optical crystal

A semi-organic nonlinear optical (NLO) material, lithium-p-nitrophenolate trihydrate (LPNP) was synthesized. Single crystals of dimensions 20 × 7 × 3 mm³ were harvested following the solvent evaporation technique. The functional groups present in the compound were identified from FT-IR and FT-Raman spectral analyses, and its molecular structure was confirmed. Identification of the compound was accomplished by X-ray diffraction technique (powder and single crystal XRD). The unit-cell dimensions and the morphology of the grown crystals were identified from single crystal XRD measurements. The thermal transport properties, thermal effusivity (e), thermal diffusivity (α), thermal conductivity (k) and heat capacity (C _p) were measured by the photopyroelectric technique at room temperature. Dielectric constant and dielectric loss were also measured as a function of frequency between 42 Hz and 5 MHz, and temperature between 32 and 100 °C. From optical transmittance measurements, the direct optical band gap of the LPNP crystal was estimated to be 2.47 eV. Laser damage threshold is 60.91 GW cm⁻². Powder second harmonic generation (SHG) measurement was carried out using a modified Kurtz–Perry technique. Third order nonlinear response was studied using Z-scan technique with a He–Ne laser (632.8 nm, 35 mW). The magnitude and the sign of the nonlinear absorption and nonlinear refraction are derived from a transmittance curve. The NLO parameters Intensity dependent refractive index n ₂, nonlinear absorption coefficient β and third order susceptibility χ⁽³⁾ were estimated.     

Studies on lithium l-ascorbate dihydrate: An interesting chiral nonlinear optical crystal

Lithium l-Ascorbate dihydrate (LLA) is a new metal organic nonlinear optical crystal belonging to the saccharide family. Single crystals of LLA were grown from aqueous solution. Solubility of the crystal has a positive temperature coefficient facilitating growth by slow cooling. Rietveld refinement was used to confirm the phase formation. The crystal has prismatic habit with (010), (001) and (10−1) prominent faces. Thermal analysis shows that the crystal is stable up to 102 °C. Transmission spectrum of the crystal extends from 302 nm to 1600 nm. Dielectric spectroscopic analysis revealed Cole–Cole behaviour and prominent piezoelectric resonance peaks were observed in the range of 100–200 kHz. Second harmonic generation (SHG) conversion efficiency of up to 2.56 times that of a phase matched KDP crystal was achieved when the (010) plate of LLA single crystal was rotated about the +ve c axis, by 9.4° in the clockwise direction. We also observed SHG conical sections which were attributed to noncollinear phase matching. The observation of the third conical section suggests very high birefringence and large nonlinear coefficients. A detailed study of surface laser damage showed that the crystal has high multiple damage thresholds of 9.7 GW cm⁻² and 4.2 GW cm⁻² at 1064 nm and 532 nm radiation respectively.     

Studies on growth and characterization of an NLO crystal: L-alanine hydrogen chloride (LAHC)

A nonlinear optical (NLO) salt viz. L-alanine hydrogen chloride (LAHC) has been synthesized and solubility of the synthesized salt in de-ionized water was determined at different temperatures. Single crystals of L-alanine hydrogen chloride (LAHC) salt were grown by solution method with slow evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction (XRD) and powder XRD analyses to study the crystal structure. The crystallinity of LAHC crystal was confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. FTIR study was used to confirm the presence of various functional groups in the grown crystals. UV–visible transmittance spectrum was recorded to study the optical transparency of LAHC crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz–Perry powder test. The density of LAHC crystal was determined by floatation method. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to TG/DTA analyses. The dielectric behavior of the sample was also studied.     

Experimental and theoretical characterization of semiorganic nonlinear optical material l-leucine hydrobromide

Semiorganic nonlinear optical material l-leucine hydrobromide (LEHBr) has been synthesized and single crystals were grown by solvent evaporation method at a constant temperature of 35 °C. CHN test, FTIR and XRD analysis were performed for identification of the material. Thermal and mechanical stability of the grown crystal were investigated by DTA-TGA analysis and microhardness measurement respectively. Suitability of LEHBr for NLO application was studied by optical transmission study and second harmonic generation (SHG) efficiency measurement. SHG efficiency was found to be 4 times of KDP. First hyperpolarizability, dipole moment and polarizability of LEHBr were calculated at the framework of Hartree–Fock (HF) with 6-311G(d) basis set. First order hyperpolarizability was found to be 3.233 × 10⁻³³ esu which is 4.9 times of urea.     

Microhardness,chemical etching,SEM, AFM and SHG studies of novel nonlinear optical crystal – l-threonine formate

The crystal l-threonine formate, an organic NLO crystal was synthesized from aqueous solution by slow evaporation technique. The grown crystal surface has been analyzed by scanning electron microscopy (SEM), chemical etching and atomic force microscopy (AFM). SEM analysis reveals pyramidal shaped minute crystallites on the growth surface. The etching study indicates the occurrence of etch pit patterns like striations and step like pattern. The mechanical properties of LTF crystals were evaluated by mechanical testing which reveals certain mechanical characteristics like elastic stiffness constant (C₁₁) and young's modulus (E). The Vickers and Knoop microhardness studies have been carried out on LTF crystals over a range of 10–50 g. Hardness anisotropy has been observed in accordance with the orientation of the crystal. AFM image shows major hillock on growth surface. The second harmonic generation (SHG) efficiency has been tested by the Kurtz powder technique using Nd:YAG laser and found to be about 1.21 times in comparison with standard potassium dihydrogen phosphate (KDP) crystals.     

Growth and characterization of dexterous nonlinear optical material: Dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP)

The crystals (dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol [DMAPNP] suitable for NLO applications were grown by the slow cooling method. The solubility and metastable zone width measurement of DMAPNP specimen was studied. The material crystallizes in the orthorhombic crystal system with noncentrosymmetric space group of P2₁2₁2_1. The ocular precision in the intact visible region was found to be good for non-linear optical claim. Quality of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of DMAPNP sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The third order nonlinear optical properties of DMAPNP crystals were premeditated by Z-scan method. Birefringence and optical homogeneity of the crystal were evaluated using modified channel spectrum method. The half wave voltage of the grown crystal deliberate from the elector optic experimentation. Photoconductivity measurement specified consummate of inducing dipoles owing to brawny incident radiation and also disclose the nonlinear activities of the grown specimen.     

The growth of l-Glutamic acid hydrochloride crystals by Sankaranarayanan-Ramasamy (SR) method

An efficient semiorganic nonlinear optical crystal l-Glutamic acid hydrochloride has been grown by using the novel uniaxial crystal growth method of Sankaranarayanan and Ramasamy with a slight modification in the experimental setup. This method allows the crystals to grow in one specified axis with well developed facet. The grown crystal has a cylindrical morphology with good optical quality. The grown crystal has been characterized by powder X-ray diffraction and UV-Vis-NIR analyses. The NLO efficiency of the crystal has been confirmed by using the Kurtz powder technique.     

Materials synthesis,crystal growth and third nonlinear optical properties of semiorganic crystal: 4-dimethylaminopyridine lithium nitrate (DMAPLN) crystal

4-dimethylaminopyridine lithium nitrate crystal (4-DMAPLN) was synthesized by the slow evaporation solution growth technique. The titular crystal was subjected to various studies to recognize its physicochemical properties. The crystalline nature and orthorhombic crystal system were revealed by single crystal and powder XRD. FTIR spectroscopy study confirms the various modes of vibrations available in the titular crystal. Linear optical studies show the lower cut-off wavelength of 280 nm with an optical bandgap value (E_g) of 4.3 eV. The electrical behavior of the 4-DMAPLN crystal was studied using dielectric studies. The mechanical behavior of the grown crystal was analyzed using the Vicker’s microhardness study, revealing that the grown crystal belongs to the hard category. The second-order nonlinear optical (NLO) behavior of 4-DMAPLN crystal was measured using Kurtz–Perry powder techniques and it was found to be 1.17 times higher than reference KDP. Z-scan analysis reveals 4-DMAPLN is a suitable candidate for optical limiting applications.

     

Growth and characterization of cobalt thiourea sulfate,a new nonlinear optical material

A new semi-organic nonlinear optical crystal of cobalt thiourea sulfate (CTS) has been grown by solvent evaporation solution growth method at room temperature. The unit cell parameters were evaluated by single crystal X-ray diffraction technique. The vibrational frequencies of various functional groups in the crystals have been derived from FT-IR analysis. The range and percentage of optical transmission are ascertained by recording the UV–VIS–NIR spectrum. The thermal behavior of the crystals has been investigated by DTA and TGA analyses. The mechanical property of the grown crystals has been analyzed by Vicker's microhardness method. The NLO property of the grown crystal has been confirmed by the Kurtz powder second harmonic generation (SHG) test.     

Growth and Characterization of Organic NLO Crystal:β-Naphthol

Single crystals of β-Naphthol(βN),an organic nonlinear optical(NLO) material was successfully grown by temperature lowering method using chloroform as solvent.The initial compound was purified by repeated recrystallization process.As-grown crystals were characterized by single crystal X-ray diffraction(XRD) studies to ascertain that βN crystal crystallized in the monoclinic system with a noncemtrosymmetric space group.Vibrational frequencies of various functional groups in the crystals were derived from Fourier transform infrared(FTIR) spectroscopy and proton nuclear magnetic resonance(NMR) spectrum.Optical characterization was done using UV-Visible near-infrared(NIR) spectroscopy.The thermal behaviour of the material was studied by thermo gravimetric and differential thermal plots.Scanning electron microscopy(SEM) study was carried out on the surface of the grown crystals to investigate the nature of defects in the crystal surface and the NLO property of the crystal was tested by Nd:YAG laser as a source.