Low Temperature Solution Growth Method Research Articles

Growth, spectral, optical, and dielectric studies on novel semiorganic NLO single crystal: d-phenylglycine hydrochloride

Good quality novel semiorganic nonlinear optical single crystal of d-phenylglycine hydrochloride has been grown from the aqueous solution by low temperature solution growth method. X-ray diffraction reveals that the crystal crystallises into orthorhombic system with noncentrosymmetric space group P212121. Experimental parameters are evaluated based on single-crystal XRD and the calculated values of the polarisability were compared with the values of polarisability using Clausius–Mossotti equation. The functional groups present in the grown crystal were confirmed by Fourier transform infrared spectral analysis. The 1H and 13C FT–NMR has been recorded to elucidate the molecular structure. Ultraviolet–visible-near infra-red absorption studies on this crystal reveal that the minimum absorption region is around 228 nm. The optical band gap of the crystal was found to be 2.9 eV. The scanning electron microscope study has been carried out to determine the surface morphology of the grown crystal. Photoluminescence studies show that the material emits violet fluorescence. Thermal studies bring forth that the crystal is thermally stable up to 255 °C. Dielectric studies reveal that both the dielectric constant and dielectric loss decrease with the increase in frequency as like the typical semiorganic nonlinear optical crystals such as bisthiourea zinc chloride, bisthiourea cadmium chloride and l-arginine dihydrogen phosphate. Electrical conductivity measurements were carried out and the Arrhenius plot is used to determine the value of activation energy. The Kurtz powder analysis on the crystal confirms the existence of second harmonic generation properties. The SHG efficiency was found to be 1.15 times that of KDP crystal.

Optoelectronic Properties of Nanostructured ZnO Thin Films Prepared on Glass and Transparent Flexible Clay Substrates by Hydrothermal Method

In the present work, transparent flexible polymer-doped clay (P-clay) substrates were successfully prepared for flexible hybrid organic–inorganic light emitting diode (HyLED) applications. The thermogravimetric–differential thermal analysis (TG–DTA) curves showed that the thermal resistance of P-clay film was higher than that of plastic substrates. Then indium doped tin oxide (ITO) thin films were prepared on newly fabricated P-clay substrates by ion-beam sputter deposition (IBSD) method. The as-prepared ITO/P-clay samples were annealed at 220 °C for 1 h. The optical transparency and electrical conductivity of annealed ITO film on P-clay with smooth surface were better than that of P-clay with rough surface. ZnO seed layers were prepared on annealed ITO/P-clay, ITO/glass, and clay substrates by IBSD method. Surface morphology study showed that the ZnO seed layer coated ITO/P-clay substrate with smooth surface was very suitable for growing vertically aligned ZnO nanorod arrays. The structural study showed that the ZnO nanorod arrays grown by low-temperature solution growth method have good crystallinity and high purity. Optical study showed that the as-prepared ZnO nanorod arrays have excellent optical properties.

Effect of Neodymium on the Growth of Sulphamic Acid Single Crystal.

Growing crystals increases, day by day due to their remarkable applications. In the present work we are interested in investigating the effect of the dopant in the crystal structure and general characterization of pure Sulphamic Acid (SA) single crystal. Hence, neodymium doped Sulphamic Acid (Nd:SA) single crystal was grown by low temperature solution growth method. The presence of neodymium in the grown crystal was confirmed by EDAX spectrum. The cell parameters of the grown crystal were determined by single crystal X-ray diffraction. The functional groups of the grown crystal were anlysed by FT-IR study. Thermal and UV-vis-NIR transmission studies were performed to know the thermal and optical behaviours of the grown crystal. The non linear optical behavior was confirmed by Kurtz – Perry powder technique. Keywords: Growth from Solution, X-ray Diffraction, FTIR, Optical Studies, Powder X-ray Diffraction, EDAX

Study on Growth Habit, SHG and Thermal Properties of Urea Phosphate Doped KDP Crystals

Pure and doped with Urea Phosphate single crystals of Potassium Dihydrogen Phosphate (KDP) were grown by the low temperature solution growth method, adopting the technique of slow evaporation of the solvent for nonlinear optical applications. The change in the growth habit of the doped KDP crystals has been reported. The study confirms the decrease in the growth rate along c-axis with increasing the dopant concentration. The doping of the Urea Phosphate in the grown crystal has been confirmed qualitatively by the FT-IR spectroscopy. Form the UV-Visible -NIR transmission study; it was observed that the transparency of the crystal increases with dopant concentration. Thermo Grav imetric Analysis shows that the thermal stability of the crystal decreases with dopant concentration. The crystal structure of doped crystal was determined fro m Powder X-Ray diffract ion studies. The improvement in Second Harmon ic Generation efficiency of doped crystal has also been reported.

Investigations on the mechanical, optical and structural properties on L-methionine-doped triglycine sulfate single crystals

Single crystals of L-methionine-doped triglycine sulfate (LMTGS) were grown by the low temperature solution growth method. The influence of the dopant on the morphological changes has been studied and reported. The grown crystals were characterized using Laue X-ray diffraction, microhardness and polaroid absorption studies.

Studies on structural, electrical and optical properties of dibromo bis(triphenyl phosphine oxide)cadmium(II) single crystal

Single crystals of semi-organic optical material dibromo bis(triphenyl phosphine oxide)cadmium(II)[CdBr2(TPPO)2] were grown by low temperature solution growth method. The composition of grown crystals was confirmed on the basis of energy dispersive analysis of X-ray (EDAX). The optical band gap of the material was calculated from the UV–Visible–NIR spectral analysis performed. Dielectric constant and dielectric loss were measured as a function of frequency and temperature. Study confirmed the contribution of space charge polarization. Also, ac resistivity and conductivity were calculated. The growth features were observed by etching study.

Violet-blue LEDs based on p-GaN/n-ZnO nanorods and their stability

In this paper, we report a fabrication, characterization and stability study of p-GaN/n-ZnOnanorod heterojunction light-emitting devices (LEDs). The LEDs were assembled fromarrays of n-ZnO vertical nanorods epitaxially grown on p-GaN. LEDs showedbright electroluminescence in blue (440 nm), although weaker violet (372 nm) andgreen-yellow (550 nm) spectral components were also observed. The device characteristicsare generally stable and reproducible. The LEDs have a low turn-on voltage (∼5 V). Theelectroluminescence (EL) is intense enough to be noticed by the naked eye, at an injection current as lowas ∼ 40 µA (2.1 × 10 − 2 A cm − 2 at 7 V bias). Analysis of the materials, electrical and EL investigationspoint to the role of a high quality of p–n nano-heterojunction whichfacilitates a large rectification ratio (320) and a stable reverse current of 2.8 µA (1.4 × 10 − 3 A cm − 2 at 5 V). Stability of EL characteristics was investigated in detail. EL intensity showed systematicdegradation over a short duration when the LED was bias-stressed at 30 V. At smaller bias (<20 V) LEDs tend to show a stable and repeatable EL characteristic. Thus a simple lowtemperature solution growth method was successfully exploited to realize nanorod/filmheterojunction LED devices with predictable characteristics.

Crystal growth and characterization of dibromo bis(triphenylphosphine oxide) cadmium (II)

Single crystals of semi-organic nonlinear optical material, dibromo bis(triphenylphosphine oxide) cadmium(II) (CdBr 2(TPPO) 2) were grown by low temperature solution growth method. The synthesized material was purified by the process of repeated recrystallization. Prepared compound was confirmed using Fourier transform infrared and proton NMR spectral analyses. The unit cell dimensions were determined by single crystal X-ray diffraction studies. Single crystal X-ray diffraction study shows that CdBr 2(TPPO) 2 crystallizes in the triclinic system. The grown crystal was characterized by UV–vis–NIR and micro hardness studies. The thermal stability of CdBr 2(TPPO) 2 was estimated from the thermogravimetric and differential thermal analyses. The second harmonic generation efficiency of powdered CdBr 2(TPPO) 2 was determined for CdBr 2(TPPO) 2 by the Kurtz and Perry method and is ∼1.2 times that of potassium dihydrogen phosphate.

Growth, Thermal, Mechanical and Dielectric Studies of Glycine Doped Potassium Acid Phthalate Single Crystals

Single crystals of glycine doped potassium acid phthalate (KAP) have been grown from low temperature solution growth method by employing slow evaporation of the solvent at room temperature. The grown crystal was subjected to various studies such as X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV-visible and Second Harmonic Generation (SHG) studies. The thermal stability, mechanical strength and dielectric constant were also measured. The various studies revealed the influence of the glycine on KAP and the investigations indicated that glycine played an important role in the changes of the spectral, optical and mechanical properties of KAP crystals.

Synthesis, crystal growth and characterization of a metal-organic nonlinear optical tri-allylthiourea mercury chloride single crystals

Metal-organic nonlinear optical material tri-allylthiourea mercury chloride single crystal was grown using low temperature solution growth method. The growth parameters such as pH and temperature were optimized for getting colorless single crystals. The X-ray rocking curve measurement shows that the grown crystal was free from internal structural grain boundaries. The structural, spectral, optical and thermal properties of the grown specimen were studied using various characterization techniques. The defects present in the grown crystals were studied with chemical etching analysis. The results show that the grown crystals are suitable candidates for nonlinear optical applications.

Crystal growth and characterization of Deuterated Glycine Phosphite single crystals

Deuterated Glycine Phosphite single crystals were grown by low temperature solution growth method using high purity deuterated water as solvent. Deuteration content of the as grown crystals was improved by repeated recrystallisation process. Structural perfection, transparency and the functional groups present in the grown crystals were identified using different characterization analyses. Dielectric behaviors of the as grown specimens were examined through thermal and impedance analysis. Partial deuteration of the grown crystal was confirmed from the DSC and dielectric results.

FT-IR, Thermal and NLO Studies on Amino Acid (L-Arginine and L-Alanine) Doped KDP Crystals

Single crystals of pure and amino acid (L-arginine and L-alanine) doped potassium dihydrogen phosphate (KDP) for second harmonic generation have been grown from low temperature solution growth method by employing slow evaporation of the solvent. FT-IR spectrum of pure and doped KDP crystals confirms qualitatively the doping of the L-arginine and L-alanine in the host crystals. UV-visible spectroscopy shows the improvement in the transparency. Crystal structure has been studied by powder X-ray diffraction. Modification in the lattice parameters has been observed. Improvement in the SHG efficiency was studied by the Kurtz and Perry method. Thermal analysis has been performed on the grown crystals.

Synthesis, spectral and thermal studies of new nonlinear optical crystal: l-valinium fumarate

An organic nonlinear optical material, l-valinium fumarate (abbreviated as LVF) has been successfully synthesized and good quality single crystals have been grown by low temperature solution growth method. The purified form of LVF is achieved by repeated crystallization. The cell parameters of LVF have been determined using single crystal X-ray diffraction technique and the crystal system is found as monoclinic. From the UV–Vis–NIR absorption spectrum, the good transparency is revealed from 300 nm to 1100 nm. The mode of vibration of different molecular groups present in LVF was identified by FT-IR spectral analysis. The thermogravimetric (TGA) and differential thermal analysis (DTA) studies show the thermal behavior and crystal was thermally stable up to 266 °C. Second harmonic generation (SHG) conversion test was made to explore the nonlinear optical behavior of this material using Kurtz and Perry method.

Second harmonic generation of a new nonlinear optical material l-valine hydrobromide

Synthesis and single-crystal growth of a new nonlinear optical crystal l-valine hydrobromide (VHBr) is reported here. Low-temperature solution growth method was employed to grow bulk single crystal of VHBr. The grown crystals were characterized by single-crystal X-ray diffraction analysis, Fourier transform infrared, UV–Vis–NIR spectral studies and dielectric measurement. Thermal stability of VHBr has been studied by DTA–TG and DSC analysis. DSC studies reveal the possibility of ferro–para phase transition in VHBr at 118 °C, which is further confirmed by dielectric measurement with respect to temperature. Kurtz powder second harmonic generation (SHG) measurement confirms the nonlinear optical (NLO) property of the grown crystal and SHG value is comparable to urea. Morphology of the grown crystal is also determined by using crystallographic data.

Template Growth of ZnO Nanorods and Microrods with Controllable Densities

ZnO nanorod/microrod arrays with controllable surface distribution densities were successfully synthesized on glass substrates via a low-temperature template-assisted aqueous solution growth method. The influences of the pH of the solution on the formation and continuing growth of ZnO crystals were studied. It was found that the variation of pH in the reaction system significantly affects the density of homogeneous nucleation on the template surface. With a low surface density of the nanorod arrays, the effects of solution composition on the growth of ZnO crystals can be clearly revealed, and these have been demonstrated with the formation of ZnO nanorods in Zn2+ + Al3+ + HMT solutions.

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

AbstractSingle 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 &amp; Co. KGaA, Weinheim)

GROWTH AND SURFACE MORPHOLOGY OF {101} CLEAVAGE PLANES OF L-ARGININE TRIFLUOROACETATE CRYSTALS

Single crystals of nonlinear optical material, L-arginine trifluoroacetate (abbreviated as LATF), were grown from an aqueous solution by the low temperature solution growth method. The cell parameters of the grown crystal were determined by the X-ray powder diffraction analysis. Atomic force microscopy (AFM) was used to investigate the surface morphology of {101} cleavage faces of LATF. Straight steps and two-dimensional nuclei were observed. Liquid inclusions and impurities as defects for revealing macrosteps were demonstrated. The molecular structure and crystal structure correlative with surface morphology were discussed.

Growth of aligned arrays of ZnO nanorods by low temperature solution method on Si surface

We report growth of ZnO nanorods by low temperature (<100°C) solution growth method. The substrates (Si, glass and fused Quartz) were seeded by pre-coating with ZnO nanoparticles (4–7 nm diameter) prepared by chemical precipitation route. Nanorods were grown on the seeded substrate in aqueous solution of Zinc Nitrate and Hexamethylenetetramine (HMT). The growth process lasts for up to 8 h and at the maximum time of growth, the nanorods have a width of ∼230–250 nm and length of ∼1.5–1.6 μm. The growth process after some initial growth (<2 h) preserves the aspect ratio and leads to about 90% texturing along the (002) direction. The growth of the nanorods was studied with time and observed growth data suggests a two-stage growth process. The nanorods have a well-defined hexagonal morphology and have a Wurtzite structure. The nanorods were characterized by different techniques and have a band gap of 3.25 eV.

Growth and characterization of a new metal-organic crystal: Potassium thiourea iodide

Single crystals of potassium thiourea iodide (PTI), a semiorganic nonlinear optical crystal, have been grown from low temperature solution growth method by a slow evaporation technique at room temperature. Single crystal X-ray diffraction pattern and FTIR spectrum analysis has confirmed the formation of the new crystal. PTI has good optical transmission in the entire visible region, which is an essential requirement for a nonlinear crystal.

Growth and characterization of Bis Thiourea Zinc Acetate (BTZA)

AbstractSingle crystals of BTZA have been grown by low temperature solution growth method using slow cooling process at an optimized pH of 3.5. The grown crystals have been examined under an optical microscope to study its surface morphology. The morphological studies show that the growth takes place by spreading of growth layers. Formation of rectangular shaped etch pit on the as‐grown crystal has been explained in relation to the growth conditions. Single crystal X‐ray diffraction analysis has been carried out to confirm the monoclinic system. Transmission spectrum reveals that the crystal has a low UV cut off of 434.5 nm and has a transmittance of 100%. Dependence of micro hardness on load has been studied. Powder X‐ray Diffraction and FT‐IR have been carried out to characterize the grown crystals. BTZA forms metal – sulfur bond and has good optical transmission in the entire visible region, which is the essential requirement for a non‐linear crystal. (© 2005 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)