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In this study, pure SnO2 and V2O5/SnO2 nanocomposite thin film NH3 sensors with varying V2O5 contents were successfully prepared by spray pyrolysis method. The prepared thin films were characterized by X-ray diffraction, Field emission scanning electron microscopy, Energy dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, stylus profilometry and Ultra violet–Visible and transmittance spectroscopies. NH3 gas sensing property was also studied. XRD results suggested that all the thin films exhibited a tetragonal rutile crystal structure, while the average crystallite size increases with V2O5 content. FESEM images of the thin films showed the presence of both nano and micro-sized grains in the range ~ 53–194 nm. EDX spectra confirmed the inclusion of V2O5 into the SnO2 matrix. The vibrational bands associated with the thin films were verified from the FTIR spectra. Thickness measurements revealed that the thickness increases with V2O5 content. Change in transparency and bandgap narrowing were also noticed from the transmittance and UV–Vis spectra. NH3 gas sensing measurements suggested that the transient resistance of V2O5/SnO2 thin film was lower than pure SnO2. Further, in the operating temperature 300 °C and 100 ppm NH3 gas, the sensor response of V2O5/ SnO2 thin film (99.13) is found to be higher than pure SnO2 thin film (92.34). Also, the response and recovery times of pure SnO2 thin film (30 and 44 s) are lower than V2O5/SnO2 thin film (39 and 180 s). These results indicate that V2O5/SnO2 thin film could serve as a suitable material for NH3 gas sensing application. [ABSTRACT FROM AUTHOR]

SnS could have novel applications in optoelectronics including solar cell devices, sensors, batteries and also in biomedical sciences. Fe-doped SnS thin films were prepared on glass substrates using chemical spray pyrolysis (CSP) method. Pure and Fe-doped SnS thin films were deposited onto microscopic glass substrates using the spray pyrolysis technique. The precursors of SnCl2·2H2O (0.1 M) and thiourea (0.1 M) were dissolved separately in a solution containing deionised water and isopropyl alcohol in proper ratio. Equal volumes of these two solutions were mixed together and sprayed onto the microscopic glass substrates at a substrate temperature of 450°C. Fe was doped with SnS thin films using FeCl3 (5 at.%, 7 at.%, 9 at.%, and 11 at.%) as the dopant source. Structural, optical, vibrational, structural, morphological properties were studied. [ABSTRACT FROM AUTHOR]

A semiorganic crystal of Boricacid potassium acetate has been grown by low temperature solution growth technique at room temperature using deionized water as a solvent. The crystalline nature of the compound was confirmed by the sharp and well defined peaks observed from the powder X-ray diffraction pattern. By single crystal X-ray diffraction method, the structure of the grown crystal has been studied. The Boric acid Potassium Acetate (BAPA) crystal has good optical transmittance in the entire UV visible region. FT-IR and FT-Raman spectral studies were performed to identify the vibrations of functional groups. The mechanical strength of the grown crystal was determined by Vicker's micro hardness test. Photoluminescence study was carried out on the crystal. The SHG study represents the nonlinear optical efficiency of the crystal., (© 2020 The Authors.)

In the present research work, the FT-IR, FT-Raman spectra of the Bis(thiourea) Nickel chloride (BTNC) were recorded and analyzed. The observed fundamental frequencies in finger print and functional group regions were assigned according to their uniqueness region. The computational calculations were carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The present organo-metallic compound was made up of covalent and coordination covalent bonds. The modified vibrational pattern of the complex molecule associated with ligand group was analyzed. Furthermore, the (13)C NMR and (1)H NMR spectral data were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP/6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A investigation on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed., (Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.)

The novel nonlinear optical single crystal of bisthiourea nickel chloride (BTNC) was grown successfully by slow evaporation technique using water as solvent. The lattice parameters of the grown crystal have been determined by X-ray diffraction studies. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. Presence of various functional groups of BTNC was identified through FTIR and Raman spectroscopic analyses. Optical absorbance spectrum recorded in the wavelength range of UV-vis-NIR revealed that this crystal has good optical transparency in the range 200-2000 nm. The second harmonic generation test of BTNC revealed the nonlinear nature of the crystal. The BTNC crystal was analyzed by differential thermal and thermo gravimetric analysis (DTA-TGA) to obtain its thermal stability.

The organometallic crystal bisthiourea manganese chloride (BTMC) was grown by slow evaporation technique using water as solvent. The lattice parameters of the grown crystal have been determined by X-ray diffraction studies. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. The observed Raman and infrared bands were also assigned and discussed. The optical transmission spectral study revealed the transmitting ability of the crystal in the entire visible region. The TGA/DTA analysis explains the thermal stability of the investigated crystal.

Single crystals of bisthiourea cadmium bromide (BTCB), a new metallorganic material crystallizing in orthorhombic system were grown from slow evaporation solution growth. The grown crystals were characterized by X-ray diffraction, FTIR and FT-Raman spectral studies. The crystals were also subjected to TGA/DTA analysis and second harmonic generation test. The transmission characteristics of the crystal was also studied.

The semiorganic non-linear optical crystal bisthiourea magnesium sulphate (BTMS) was grown by slow evaporation technique using water as solvent. Vibrational spectra were recorded to determine the symmetries of molecular vibrations. The observed Raman and infrared bands were also assigned and discussed. The optical transmission spectral study was carried out to test the transmitting ability of the crystal in the visible range. The second harmonic generation test of BTMS revealed the non-linear nature of the crystal. The TGA/DTA curve was also recorded for the experimental crystal.