Transformation from conducting ferromagnetic to insulating diamagnetic in vanadium doped ZnO nanoparticles

Abstract

A simple cost effective approach of solution combustion method is chosen to prepare the vanadium doped ZnO nanoparticles. X-ray diffraction and Raman spectroscopy affirm the single phase formation of ZnO and evolution of secondary phase upon increasing vanadium concentration. Further lattice irregularity due to vanadium substitution is clearly manifested. Morphological aspects explored using SEM and TEM implies the alteration of hexagonal grain boundaries to spherical ones. A systematic study on the grain boundary reformation of the ZnO nanograins due to vanadium is undertaken using structural, morphological and spectroscopic characterizations. Electrical studies illustrate the individual contributions of grain and grain boundary towards the resistance of the material. Magnetization decreases with increasing vanadium concentration. Possible interplay between defect/doping and conductivity is proposed so as to explain the underlying mechanism of magnetic interactions.