Role of cationic/oxygen vacancies in transport and magnetic properties of NiFe$_{2}$O$_{4}$ thinfilms prepared by pulsed laser deposition
POSTER
Abstract
Non-stoichometric NiFe$_{2}$O$_{4}$ thin films have been synthesized pulsed laser deposition. We have found monotonic increase in saturation magnetization and non-monotonic increase in conductivity as a function of oxygen pressure during growth of the samples. Substantial reduction in magnetization is found which varies from 0.4{\%} to 40{\%} of bulk value as a function of oxygen partial pressure during the growth of the samples. Three orders of magnitude increase in the conductivity of the sample prepared at an excessive oxygen deficient environment. These variations in saturation magnetization and conductivity as been discussed within the framework of cation/oxygen vacancies in inverse spinel NiFe$_{2}$O$_{4}$ structure. The changes in the electronic structures due to the presences of the vacancies have been investigated using X-ray Photoelectron spectroscopy.