Papers by Author: A.R. Phani

Abstract: The nano crystalline nickel-cobalt ferrite using albumen (egg white) is synthesized by thermal evaporation method and its dielectric behaviour is analyzed for different annealing temperatures. The dielectric property of the sample is measured using impedance analyzer in the frequency range 1-100 MHz. The variation of dielectric constant and dissipation factor under different frequency for the samples at different annealing temperature are analyzed. A steady dielectric constant is observed for the sample annealed at 500°C. The dielectric constant obtained for this sample is low and it is in the range of 18.9 to 6.9 for different frequencies. This low value of dielectric constant shows the less interfacial polarization due to high resistivity which may be to the presence of a few Fe2+ ions. It is observed that the dispersion in dielectric constant by varying the annealing temperature is producing an intended result. The presence of constituent phases in Ni1-xCoxFe2O4 is confirmed by X-Ray Diffraction. The particle size for Ni1-xCoxFe2O4 obtained from Scherrer equation is found to be is 30nm. The morphology, particle size and percentage composition of elements are measured by employing Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Analysis spectrum (EDX).

Abstract: Tin oxide nanoparticle was successfully prepared by the chemical digestion method from the starting material as SnCl2. The SnO2 material was characterized by X-Ray Diffraction (XRD), Transmission Electron Microscope (TEM) and Selected Area Electron Diffraction (SAED). The SnO2 was an n-type material preferred to humidity sensing property towards the moisture. The response and recovery time of sensor was calculated as 129sec and 206sec respectively. It has exhibited better efficiency compared with the bulk SnO2 material. Additional Weight loss, EDS, FT-IR and resistivity measurements were also presented.