FMR studies on nanocrystalline zinc ferrite thin films

Abstract

Ferromagnetic Resonance (FMR) studies were carried out as a function of orientation and temperature on RF-sputtered nanocrystalline thin films of ZnFe2O4 having saturation magnetization (MS) of 230 emu/c.c. The in-plane FMR linewidth (ΔH) increases and the resonance field (HR) decreases with decrease in temperature. The annealing of the film in air at 500 °C for 3hrs decreases ΔH confirming disorder as the source of FMR line broadening for the as deposited films. The effective magnetization (4πMeff) of 1725 G and gyromagnetic ratio (γeff) of 3.08 GHz/kOe were estimated using Kittel's equations. The uniaxial anisotropic field of 1164 Oe observed for the film is assigned to preferential orientation of grains.