Effect of in-situ oxidation on structure and ferromagnetic properties of Fe3Al and FeAl2O4 thin films prepared by electrodeposition

Abstract

Magnetic oxide thin films are potentially important in the coming era in data storage and spintronic devices. But the effects of oxygen positional parameter on different properties of oxide thin films are not completely understood and scarcely reported. Using DC electro-deposition, FeAl2O4 thin films were deposited on copper substrates by in-situ oxidation of intermetallic Fe3Al at 2 V. Deposition time for each intermetallic film was a 30 min while oxidation time was varied from 0 min to 30 min with the interval of 5 min. All the thin films were annealed for 1 h at 300 °C in the 500 Oe magnetic field. XRD patterns confirmed the formation of spinel structure for the FeAl2O4 thin films with no preferred orientation. Variations in lattice parameters and crystallite size might be due to surface activation energy and in cooperation of oxygen atoms at the tetrahedral sites for charge compensation. Cation distribution and lowest stacking fault probability confirmed the formation of defect free pure phase of FeAl2O4 for the thin film with the 30 min oxidation. Tolerance factor found to very close to unity representing the formation of defect free thin films. Magnetic results showed that all the thin films carried the ferromagnetic behavior and FeAl2O4 thin film with the 30 min oxidation carried maximum saturation magnetization.