Bis Thiourea Zinc Acetate Research Articles

Experimental analysis of pure and l-tyrosine influenced bis-thiourea zinc acetate (BTZA) crystal for NLO device applications

In present research article the single crystal has been grown and change in traits of BTZA crystal has been evaluated by comparative approach. The single crystal X-ray diffraction technique has been utilized to determine the structural configurations of pure and LT influenced BTZA crystal. LT influenced BTZA sample has been subjected to energy dispersive spectroscopic technique to find out the chemical composition. The UV–vis spectral analysis has been carried out within 200−900 nm to explore rise in transmittance of BTZA crystal due to LT. The prominent increase in frequency doubling efficiency of LT influenced BTZA crystal has been confirmed by means of Kurtz-Perry test. The temperature dependence of electrical parameters of pure and LT influenced BTZA crystal has been comparatively evaluated confined to 30−100 °C range. The thermal stability of LT influenced BTZA crystal has been performed within 40−400 °C by thermogravimetric and differential thermal analysis (TG-DTA).

Phenol red dyed Bis thiourea Zinc acetate crystal growth and characterization for electro-optic applications

In current work, the growth of dyed Bis thiourea Zinc acetate single crystals of size ∼30 mm × 7 mm × 5 mm is achieved by solution technique. X-ray diffraction and FT-IR spectroscopy are used to verify crystal structure and functional groups. Intensity of diffraction peaks confirms good crystalline nature of dyed Bis thiourea Zinc acetate crystals than pure. Two absorption bands at ∼387 and 558 nm were observed in diffused reflectance spectra of dyed crystals. The energy gap was calculated for both crystals and establishes to be ∼4.87 eV for pure and ∼4.93 eV for dye crystals. Photoluminescence spectra were recorded and a green emission band was observed in dyed Bis thiourea Zinc acetate crystal at ∼513 nm was observed in dyed crystal. The grown crystals are found to be thermally stable up to 195 °C confirmed by differential scanning calorimetry. The value of dielectric permittivity is found to be reduced in dyed crystal. Microhardness of dyed crystals is much better than pure crystal. Surface study shows that the dyed crystals contain lesser defects than pure. Hence, the improved properties of dyed Bis thiourea Zinc acetate make it more useful than pure in electro-optic devices.

Single crystal growth and enhancing effect of glycine on characteristic properties of bis-thiourea zinc acetate crystal

A single crystal of glycine-doped bis-thiourea zinc acetate (G-BTZA) with a dimension of 15 × 6 × 4 mm3 has been grown using the slow solution evaporation technique. The structural parameters of the crystals were determined using the single crystal XRD technique. The increase in optical transparency of the doped BTZA crystal was ascertained in the range of 200 to 900 nm using UV–visible spectral analysis. The improved optical band gap of the G-BTZA crystal is found to be 4.19 eV, and vital optical constants have been calculated using the transmittance data. The influence of glycine on the mechanical parameters of the BTZA crystal has been investigated via microhardness studies. The thermal stability of pure and doped BTZA crystals has been determined by employing the thermogravimetric and differential thermal analysis technique. The improvement in the dielectric properties of the BTZA crystal after the addition of glycine has been evaluated in a temperature range of 30 to 120 °C at a frequency of 100 KHz. The SHG efficiency of the glycine-doped BTZA crystal is found to be much higher than KDP and BTZA crystal material in a Kurtz–Perry powder analysis.

Synthesis, structural, topographical, linear and nonlinear optical, electrical and mechanical properties of Bisthiourea zinc acetate single crystal

Nonlinear optical material Bisthiourea Zinc Acetate (BTZA) was synthesized by slow evaporation solution growth technique. The grown crystals were characterised by Single crystal XRD and powder XRD studies. The presence of functional groups and the co-ordination of metal ions to Thiourea were confirmed by FTIR analysis. The UV-vis –NIR spectrum shows a low absorption in the entire visible and IR region. Optical band gap of the grown crystal was found to be 4.18 eV. The photoluminescence studies carried out and the crystal has blue emission. The Refractive Index was determined experimentally for the first time and found to be 1.508 for the incident wavelength of 632.8 nm. The second harmonic generation efficiency was determined using Kurtz and Perry powder technique and it was 0.7 times than that of the KDP crystal. Thermal properties were studied by thermo gravimetric analysis and differential thermal analysis. Dielectric studies were carried out at different frequencies for various temperatures. The mechanical behaviour of the grown crystal was studied using Vickers micro hardness tester. The growth mechanism and surface features are investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM).

Study of growth condition and characterization of bisthiourea–zinc acetate (BTZA) crystal grown in silica gel

Semiorganic crystals of bisthiourea–zinc acetate (BTZA) having nonlinear optical properties was grown in silica gel medium by gel technique at room temperature. The optimum pH, yielding maximum size (35mm) of transparent title crystal was found to be 4.8 pH. Single crystal XRD analysis reveals that the crystal lattice of BTZA crystal belongs to monoclinic system with cell parameter, a=7.1243Å, b=17.7292Å and c=11.1372Å. The presence of functional groups in the crystals was confirmed by FTIR analysis, and also the presence of elements in the compound was identified by EDAX. The optical constants (lower cutoff wavelength λ=297nm, band gap energy=4.4022eV) were determined using the recorded UV–Vis–NIR spectrum of BTZA crystal. A surface feature of the crystal was analyzed using AFM (Atomic Force Microscope). The Vickers microhardness number was found to increase with increasing load, and the yield strength (σy), elastic stiffness constant (C11) of BTZA crystal were calculated. The laser damage threshold was measured using Nd:YAG laser (1064nm). The dielectric properties of BTZA crystal was recorded in the frequency range of 50Hz–5MHz, and it shows that the dielectric constant and dielectric loss is found to be decreased with an increase of frequency at various temperature. Further, the valence electron, plasma energy and electronic polarizability for the gel grown BTZA crystal was calculated. Thermal behavior of the gel grown crystal was investigated by thermo gravimetric and differential scanning calorimetric analysis.

Polymer and surfactant-templated synthesis of hollow and porous ZnS nano- and microspheres in a spray pyrolysis reactor.

Nanostructured zinc sulfide can provide unique photonic, electronic, and catalytic properties that are of interest for applications ranging from bioimaging to photocatalysis. Here we report an easily controllable continuous method to produce porous and hollow ZnS nano- and microspheres. We used poly(ethylene glycol) methyl ether (PEG), polyvinylpyrrolidone (PVP), ethylene oxide/propylene oxide block copolymer (Pluronic F-38), and cetyltrimethylammonium bromide (CTAB) as templates to synthesize ZnS nano- and microspheres with controlled internal morphology in a spray pyrolysis process, starting from an aqueous solution of chemical precursors and templating agents. Spherical particles were produced by droplet-to-particle conversion of droplets. Zinc acetate and thiourea, used here as precursors for ZnS, react in solution to form bis-thiourea zinc acetate (BTZA), which precipitates with the evaporation of solvent. Upon further heating, BTZA decomposes to yield ZnS. During solvent evaporation, PEG and Pluronic precipitate after BTZA, driving formation of a shell of ZnS and a hollow core. In contrast, PVP and CTAB interact strongly with BTZA and ZnS, such that the PVP and ZnS remain intermixed. After evaporation of solvent, the templating agents can be pyrolyzed at high temperature to leave behind porous or hollow ZnS microspheres composed of many much smaller nanocrystals.

Growth and characterization of BTCS and BTZA crystals grown by slow evaporation method

Good quality Bisthiourea Cadmium Sulphate (BTCS) and Bisthiourea Zinc Acetate (BTZA) crystals have been grown by simple slow evaporation method. From the powder X-ray diffractograms it is found that BTCS crystal belongs to orthorhombic system, whereas BTZA crystal belongs to Tetragonal system. The FTIR analysis reveals that the CS stretching frequencies of both BTCS and BTZA shows a shift to lower frequencies when compared to pure thiourea, which may be attributed to the reduced double bond character of CS bond on coordination. UV–vis spectroscopic studies show that the grown crystals have high transparency in entire visible region and NIR region. The hardness of the crystals have been studied using Vicker's microhardness test and it was found that the BTZA crystals show better hardness when compared to BTCS crystals.

Quantum chemical computational studies on bis-thiourea zinc acetate

In this study, quantum chemical calculations of vibrational spectra, Raman spectra, electronic properties (total energy, dipole moment, electronegativity, chemical hardness and softness), Mulliken atomic charges and thermodynamic parameters of bis-thiourea zinc acetate (BTZA) have been performed using Gaussian 09 program. Additionally, nonlinear optical (NLO), conformational, natural bond orbital (NBO) analyses of BTZA have been carried out using the same program. The structural and spectroscopic data of the molecule in the ground state have been calculated using Hartree-Fock (HF) and density functional method (DFT/B3LYP) with the 6-311++G(d,p) basis set. In addition, the molecular frontier orbital energies (HOMO, HOMO-1, LUMO and LUMO+1) of the title compound have been calculated at the HF and B3LYP levels. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally, the calculated results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the experimental ones.

Investigation on the linear and nonlinear optical properties of a metal organic complex—Bis thiourea zinc acetate single crystal

The third order nonlinear optical properties of bis thiourea zinc acetate single crystal were measured using He–Ne laser (λ=632.8nm) by employing the Z-scan technique. The magnitude of nonlinear refractive index and nonlinear absorption coefficient were found to be −2.11×10−8cm2/W and −1.201×10−3cm/W respectively. The linear refractive index of the complex was measured by the Brewster angle method and was found to be 1.483. The third order non-linear optical susceptibility χ(3) was found to be in the order of 10−6esu. The negative non-linear absorption coefficient shows the defocusing nature of the complex which is an essential property required for the application in optical limiting application. The second harmonic generation efficiency of the complex was studied using the Powder Kurtz method and was found to be 1.5 times greater than that of KDP.

Growth and characterization of nonlinear optical crystal Bis Thiourea Zinc Acetate (BTZA) in the presence of l-Proline

Single crystal of 2mol% l-Proline doped Bis Thiourea Zinc Acetate (BTZA), a semi organic nonlinear optical material has been grown using slow evaporation technique. Good quality single crystal with dimension 11×7×3mm3 was harvested after 30days. The influence of amino acid l-Proline was studied for 1, 2 and 3mol% l-Proline doped BTZA using Kurtz and Perry powder second harmonic generation test. This was compared with pure BTZA which confirms the enhancement of second harmonic generation property of l-Proline doped BTZA. Better enhancement was found in 2mol% l-Proline doping. The grown crystal was characterized using single crystal X-ray diffraction, Fourier Transform Infra Red spectroscopy (FTIR) analysis, UV–Visible absorption and thermogravimetric analysis.

Effect of lithium chloride on spectral, optical, thermal and mechanical behaviour of bis thiourea zinc acetate crystals

Single crystals of pure bis thiourea zinc acetate (BTZA) and lithium chloride (LiCl) doped BTZA have been synthesized and grown successfully from aqueous solutions by slow evaporation technique. The single crystals thus grown were characterized by different techniques such as single crystal XRD, AAS, FT-IR, UV–Vis, TG/DTA and SHG test. The single crystal XRD study proved that the dopant has not changed the structure of the parent crystal. The AAS study confirmed the presence of lithium in the doped crystal. The FTIR study ascertained the metal coordination of lithium chloride doped BTZA through thiourea. The optical behavior of the doped crystal has been examined by UV spectral analysis. Thermal studies TGA & DTA of the doped crystal have been investigated and found that the doped crystal is thermally more stable than the pure crystal. The SHG test using Nd: YAG Laser confirmed the NLO activity of the pure and doped crystal. The obtained results are presented and discussed.

Growth and characterization of pure and doped bis thiourea zinc acetate: Semiorganic nonlinear optical single crystals

Metal–organic coordination complex single crystals bis thiourea zinc acetate (BTZA) and Cd2+ doped BTZA have been synthesized and grown successfully by slow-cooling technique from their aqueous solutions. Single crystals of pure and Cd2+ doped BTZA with dimensions of 35×4×2mm3 and 10×5×6mm3, respectively were obtained with well defined morphology. The as grown single crystals are characterized by single crystal XRD studies and melting point measurements which reveal the incorporation of metallic dopants has not changed the structure of the parent crystal. The powder X-ray diffractogram of the grown crystals has been recorded and the various planes of reflection identified shows shift in the peak positions. The metal coordination with thiourea through sulphur in pure and Cd2+ doped BTZA were ascertained by FTIR studies and optical absorption study to identify the UV cut-off range. The presence of metals in pure and Cd2+ doped BTZA crystal lattice were confirmed by atomic absorption spectroscopy (AAS). The thermal decomposition of pure and Cd2+ doped BTZA crystals were investigated by thermo gravimetric analyses (TGA) and differential thermal analysis (DTA) indicate that doped crystals are more stable than pure crystals. The dielectric response of the crystals were studied in the frequency range 100Hz–5MHz at different temperatures and the results are discussed. Second harmonic generation (SHG) measurement confirms that the pure and Cd2+ doped BTZA have nonlinear optical (NLO) property. Laser damage threshold value of 12.44MW/cm2 has been determined using Q-switched Nd:YAG laser operating at 1064nm and with 8ns pulses in single shot mode for pure BTZA single crystal is reported for the first time.

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 & Co. KGaA, Weinheim)

Investigations on the vibrational spectroscopy and on the thermal behaviour of bis-thiourea zinc acetate—BTZA

Single crystals of bis-thiourea zinc acetate (BTZA) for use as a non-linear material have been grown using solution growth technique under optimized growth conditions. Investigations have been carried out to assign the vibrational frequencies of the grown crystals. FTIR and Raman spectra were taken and compared to evaluate the molecular vibrational properties of the grown crystals. Thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) have been carried out to understand the effect of temperature-influenced weight loss and on the endothermic and exothermic characteristics of thermo-gravimetric analysis (TGA).

Metastable zone width, induction period and interfacial energy of bis thiourea zinc acetate (BTZA)

Solubility, metastable zone width and induction period measurements have been performed on bis thiourea zinc acetate (BTZA). Interfacial tension values determined from induction period measurements have been used for evaluation of the nucleation parameters. BTZA crystallizes in the monoclinic structure. The complex formation is stabilized by metal–sulfur coordination. The grown crystal possesses good optical transmission in the entire visible region, which is an essential requirement for nonlinear optical crystals.

Growth and characterization of Bisthiourea-zinc Acetate, a new nonlinear optical material

A new semi-organic nonlinear optical crystal Bisthiourea-zinc Acetate (BTZA) has been grown and characterized. The solubility study was carried out in aqueous solution. Crystals were grown from low temperature solution method by slow evaporation technique. Powder XRD and FTIR have confirmed the formation of the new crystal. UV-Vis-NIR spectra analysis showed good optical transmission in the entire visible region. The optical second harmonic generation conversion efficiency of BTZA was determined using Kurtz powder technique. The SHG efficiency was better than materials like KDP and CTA.

The crystal structure of bisthiourea-zinc acetate

Bisthiourea-zinc acetate, Zn[SC(NH2)2]2(CH3COO)2, is monoclinic, P21/c: a=6938, b= 17678, c= 11.798 A, ,8= 112.6 °, Z = 4 . The structure, solved by means of three-dimensional Fourier methods, has been refined with the use of the anisotropic differential synthesis. Zn coordinates to two S atoms from two thiourea molecules (Zn-S 2-326 and 2261/~) and to two O atoms (Zn-O 1.973 and 1 954/~k) from two acetate groups, to form a tetrahedral arrangement. Two further oxygen atoms from the same acetate groups are involved in weaker interactions with the metal atom at 2-996 and 2891 ~ ; as a consequence of these interactions the planes of the acetate ions are oriented in such a way that the Zn atom almost lies within them. There are no significant differences between corresponding bond distances and angles in the two thiourea molecules: these are much the same as in the uncoordinated thiourea.