Jiten P. Tailor

Magnetite Fe3O4 nanoparticles synthesis by wet chemical reduction and their characterization

The authors report the synthesis of Fe3O4 nanoparticles by wet chemical reduction technique at ambient temperature and its characterization. Ferric chloride hexa-hydrate (FeCl3 6H2O) and sodium boro-hydrate (NaBH4) were used for synthesis of Fe3O4 nanoparticles at ambient temperature. The elemental composition of the synthesized Fe3O4 nanoparticles was determined by energy dispersive analysis of x-rays technique. The x-ray diffraction (XRD) technique was used for structural characterization of the nanoparticles. The crystallite size of the nanoparticles was determined using XRD data employing Scherrers formula and Hall–Williamsons plot. Surface morphology of as-synthesized Fe3O4 nanoparticles was studied by scanning electron microscopy. High resolution transmission electron microscopy analysis of the as-synthesized Fe3O4 nanoparticles showed narrow range of particles size distribution. The optical absorption of the synthesized Fe3O4 nanoparticles was studied by UV–vis–NIR spectroscopy. The as-synthesized nanoparticles were analyzed by Fourier transform infrared spectroscopy technique for absorption band study in the infrared region. The magnetic properties of the as-synthesized Fe3O4 nanoparticles were evaluated by vibrating sample magnetometer technique. The thermal stability of the as-synthesized Fe3O4 nanoparticles was studied by thermogravimetric technique. The obtained results are elaborated and discussed in details in this paper.

Synthesis and electrical transport properties of SnS nanoparticles

The SnS nanoparticles were synthesized at ambient temperature by simple wet chemical method. The stoichiometric and structural characterization was done by EDAX and XRD techniques respectively. The crystallite size was determined using Scherrers formula and Hall-Williamson plot using XRD data. The electrical transport properties studies were carried out on pellets prepared by hydraulic pressing of SnS nanoparticles. The thermoelectric power and dc resistivity variation with temperature was studied on the pellets. Room temperature Hall effect measurement was made on the pellet. The obtained results are discussed in details.

Wet Chemical Synthesis and Characterization of MnS Nanoparticles

The manganese sulfide, MnS, is a wide bandgap (Eg = 3.1eV) diluted magnetic semiconductor belonging to the VIIB-VIA family with outstanding magneto-optical properties. The authors report the synthesis and characterization of MnS nanoparticles. The MnS nanoparticles were synthesized by simple wet chemical method at ambient temperature. Manganese acetate (C4H6MnO4.4H2O) was used as source for Mn+2 ions and thioacetamide (C2H5NS) was used as source for S-2 ions. The energy dispersive analysis of X-ray (EDAX) and X-ray diffraction (XRD) were used for stoichiometric and structural characterization of the synthesized nanoparticles respectively. The crystallite size calculated from XRD using Scherrer’s formula and Hall-Williamson relation came out to be of 6.81 nm and 5.27 nm respectively. The optical absorption spectra showed absorption edge at 325 nm corresponding to energy of 3.82 eV, which acknowledged the occurrence of blue shift. The photoluminescence spectra recorded for five different excitation wavelengths viz 250, 275, 280, 300 and 325 nm showed three emission peaks at 463 nm, 550 nm and 821 nm. The TEM and SEM analysis of the particles clearly shows the particles are spherical in shape. The selected area electron diffraction (SAED) pattern showed ring pattern, stating the nanoparticles to be polycrystalline. The obtained results are discussed in details.

Study of surface microstructure and optical properties of as-grown Mo0.6W0.4Se2 single crystals

The surface microstructures and optical properties of as-grown Mo0.6W0.4Se2 single crystals were studied. The microstructures on the as-grown crystal surface reveals that spirals and Frank-Read dislocations are prominent. The study of the variation of refractive index (η), extinction coefficient (k), real and imaginary dielectric constants (er and ei), and the optical conductivity (σ0) with incident photon energy from the analysis of optical absorption spectrum of Mo0.6W0.4Se2 single crystals, showed that near the bandgap energy value all sharply increases.

Thermal decomposition study of Mo0.6W0.4Se2 single crystals

The Mo0.6W0.4Se2 single crystals were grown by direct vapour transport (DVT) technique. The thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential thermogravimetric (DTG) analysis were carried out on the as-grown Mo0.6W0.4Se2 single crystals in inert nitrogen atmosphere. All these thermal analysis were done from ambient temperature to 1223 K. The activation energy, enthalpy, entropy and Gibbs free energy of Mo0.6W0.4Se2 single crystals were determined from the thermal curves using Broido, Horowitz-Metzger (H-M), Piloyan-Novikova (P-N) and Coats-Redfern (C-R) relations. The results are reported in this paper.

Chemical bath deposited and dip coating deposited CuS thin films – Structure, Raman spectroscopy and surface study

The crystal structure, Raman spectroscopy and surface microtopography study on as-deposited CuS thin films were carried out. Thin films deposited by two techniques of solution growth were studied. The thin films used in the present study were deposited by chemical bath deposition (CBD) and dip coating deposition techniques. The X-ray diffraction (XRD) analysis of both the as-deposited thin films showed that both the films possess covellite phase of CuS and hexagonal unit cell structure. The determined lattice parameters of both the films are in agreement with the standard JCPDS as well as reported data. The crystallite size determined by Scherrer’s equation and Hall-Williamsons relation using XRD data for both the as-deposited thin films showed that the respective values were in agreement with each other. The ambient Raman spectroscopy of both the as-deposited thin films showed major emission peaks at 474 cm−1 and a minor emmision peaks at 265 cm−1. The observed Raman peaks matched with the covellite phase of CuS. The atomic force microscopy of both the as-deposited thin films surfaces showed dip coating thin film to be less rough compared to CBD deposited thin film. All the obtained results are presented and deliberated in details.The crystal structure, Raman spectroscopy and surface microtopography study on as-deposited CuS thin films were carried out. Thin films deposited by two techniques of solution growth were studied. The thin films used in the present study were deposited by chemical bath deposition (CBD) and dip coating deposition techniques. The X-ray diffraction (XRD) analysis of both the as-deposited thin films showed that both the films possess covellite phase of CuS and hexagonal unit cell structure. The determined lattice parameters of both the films are in agreement with the standard JCPDS as well as reported data. The crystallite size determined by Scherrer’s equation and Hall-Williamsons relation using XRD data for both the as-deposited thin films showed that the respective values were in agreement with each other. The ambient Raman spectroscopy of both the as-deposited thin films showed major emission peaks at 474 cm−1 and a minor emmision peaks at 265 cm−1. The observed Raman peaks matched with the covellite phas...

Thermal decomposition study of manganese sulfide (MnS) nanoparticles

The as-synthesized manganese sulfide (MnS) nanoparticles were used for the thermal study. The nanoparticles were synthesized by simple wet chemical route at ambient temperature. The photoelectron binding energy and chemical composition of MnS nanoparticles was analyzed by X-ray photoelectron spectroscopy (XPS). The thermogravimetric (TG), differential thermogravimetric (DTG) and differential thermal analysis (DTA) were carried out on the as-synthesized MnS nanoparticles. The thermocurves were recorded in inert N2 atmosphere in the temperature range of ambient to 1173 K. The heating rates employed were 5, 10, 15 and 20 K/min. The thermodynamic parameters like activation energy (Ea), enthalpy change (ΔH), entropy change (ΔS) and change in Gibbs free energy (ΔG) of as-synthesized MnS nanoparticles were determined using Kissinger method. The obtained XPS and thermal results are discussed.The as-synthesized manganese sulfide (MnS) nanoparticles were used for the thermal study. The nanoparticles were synthesized by simple wet chemical route at ambient temperature. The photoelectron binding energy and chemical composition of MnS nanoparticles was analyzed by X-ray photoelectron spectroscopy (XPS). The thermogravimetric (TG), differential thermogravimetric (DTG) and differential thermal analysis (DTA) were carried out on the as-synthesized MnS nanoparticles. The thermocurves were recorded in inert N2 atmosphere in the temperature range of ambient to 1173 K. The heating rates employed were 5, 10, 15 and 20 K/min. The thermodynamic parameters like activation energy (Ea), enthalpy change (ΔH), entropy change (ΔS) and change in Gibbs free energy (ΔG) of as-synthesized MnS nanoparticles were determined using Kissinger method. The obtained XPS and thermal results are discussed.