Deposition, characterization, magnetic and optical properties of Zn doped CuFe2O4 thin films

Abstract

Nanocrystalline Zn doped Cu spinel ferrite thin films having compositional formula Cu1−xZnxFe2O4 (where x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) were deposited on glass substrate by spray pyrolysis deposition technique using nitrates of copper, zinc and ferric metals as raw materials. The deposited thin films were characterized by X-ray diffraction, infrared, field emission scanning electron microscope, energy dispersive spectra, atomic force microscope, vibrating sample magnetometer and ultra violet visible spectroscopy at room temperature. X-ray diffraction studies revealed the formation of single phase cubic spinel structure of CuZn spinel ferrite thin films. The crystallite size was determined using Debye-Scherrer's formula and found in the range of 9–20 nm. The thickness of the deposited thin films measured by spectroscopy reflectometer was found in the range of 267–247 nm. The surface morphology of the prepared thin films studied by FESEM technique exhibits the dense structure. The analysis of AFM images showed the columnar structure of the deposited thin films. The magnetic measurements showed the soft ferromagnetic behaviour except for x = 1.0; for this it shows anti-ferromagnetic behaviour. The magnetic parameters like saturation magnetization, remenance magnetization, coercivity, initial permeability and magnetic domain size were obtained from the M − H loops. The value of saturation magnetization of thin film samples increases with zinc up to x = 0.6 and decreases for further x values. The optical properties as a function of Zn content ‘x’ were investigated in order to get the both direct and indirect band gaps of thin films. The values of direct and indirect band gap increased with zinc content x except for x = 0.8 and varies from 2.04 to 2.26eV and 1.74–1.96eV respectively.