Shankar D. Birajdar

Effect of iron oxide (Fe 2 O 3 ) on the structural, optical, electrical, and dielectric properties of SrO–V 2 O 5 glasses

The oxide glass system of the composition (10 – x)SrO–xFe2O3–90V2O5, (x = 0, 2, 4, 6 and 8 mol %) were prepared by a standard melt quenching technique. The amorphous nature of the prepared glass was confirmed using X-ray diffraction technique. The infrared spectra of these glasses were recorded over a continuous spectral range (850–1500 cm–1). The density of prepared sample was obtained by the Archimedes principle. The physical parameters of the glasses were also determined with respect to the composition. Density increases from 3.10 to 3.20 g/cm3, whereas the molar volume decreases with the increase in Fe2O3 concentration. In order to study optical properties, absorption spectra were measured at room temperature. Indirect optical energy band gap, optical dielectric constant, refractive index were calculated from optical energy band gap. The refractive index decreases gradually with the increase in Fe2O3 content due to increase of bridging oxygen’s. For temperatures from 300 to 500 K, the dc conductivity increased with the increasing Fe2O3 content. The dielectric properties like dielectric constant, dielectric loss factor and dielectric loss tangent investigated at the room temperature in the frequency range of 10 kHz to 1 MHz decreases with frequency. The dielectric behavior shows strong frequency as well as composition dependence.

Investigations on the synthesis, structural and microstructural characterizations of Ba1-xSrxZrO3 nanoceramics

ABSTRACT Strontium (Sr) substituted barium zirconate (Ba1-xSrxZrO3, for x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) perovskite nanoceramics were prepared by simple, easy and cost-effective sol-gel auto combustion technique using citric acid as a fuel. X-ray diffraction (XRD) patterns confirmed the formation of cubic phase structure for x = 0.0–0.6 composition with minor impurity of carbonate. However, for x = 0.8–1.0 orthorhombic distorted perovskite structure was observed. The average crystallite size (t), lattice constant (a, b and c) and other structural parameters of Sr substituted barium zirconate nanoceramics were calculated from XRD data. The average particle size was calculated by using the Debye-Scherers formula obtained to be 18–25 nm. The average crystallite size, lattice parameter, unit cell volume and X-ray density value changes when Sr2+ ions are substituted in BaZrO3 lattice, resulting in the structural variation. The microstructural studies were investigated through scanning electron microscopy (SEM) technique. SEM confirmed the homogeneous and well defined surface morphology of the synthesized samples in nano range. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of a metal oxide band (-O-Zr-O-) for all the calcined samples. The FTIR spectra confirmed that the prepared ceramics have a cubic perovskite structure for lower Sr composition, the shifting of the major band (for x = 0.8–1.0) suggests distortion in geometry. Compositional stoichiometry was confirmed by energy dispersive spectrum (EDS) analysis.

Effect of drug Piper nigrum on physicochemical properties of zinc chloride at varying concentration and temperature investigated through ultrasonic tool

Abstract In the present study, the molecular interaction between ethanolic extract of drug Piper nigrum with (metal ions) ZnCl2 have been investigated by ultrasonic method. The ultrasonic velocity (U), density (ρ), and viscosity (η) of an ethanolic extract of drug with metal ions of different concentration (number of moles of drug = 1.4018, 2.1027, 2.8036, and 3.5045) and different temperature (T = 308.15, 313.15, 318.15, 323.15, and 333.15) K at 2 MHz have been measured through ultrasonic interferometer. From experimental parameters (ultrasonic velocity (U), density (ρ) and viscosity (η)), various thermoacoustical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), specific acoustic impedance (Z) has been calculated. The change in concentration of drug P. nigrum and varying temperature affects compressibility of solution, which gives idea about molecular interactions in liquid mixtures. Obtained experimental and thermoacoustical parameters are used to investigate the solute–solvent interactions between P. nigrum and ZnCl2 ions which is useful to understand the mechanism of their metabolism in living systems. The conclusion drawn from the ultrasonic investigation is the mixture act as structure breaker and there is a complex formation between ZnCl2 and P. nigrum for the system as a function of concentration and temperature. The results obtained from these studies are helpful for pharmacological applications of drugs, transport of drugs across biological membranes.

Polyethylene glycol coated CoFe2O4 nanoparticles: A potential spinel ferrite for biomedical applications

The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe2O4) nanoparticles have been reported in the present study. CoFe2O4 nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe2O4 nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe2O4 nanoparticles were calculated by using XRD data. The presence of PEG on CoFe2O4 nanoparticles and reduced agglomeration in the CoFe2O4 nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence m...