Structural and magnetic properties of polycrystalline Fe3O4 thin film

Abstract

The Fe3O4 thin films of 2000Å thickness have been grown at room temperature by dc magnetron sputtering technique and their structural and magnetic properties are studied. The structural study shows that the film is random polycrystalline with no preferred orientation. The isothermal in-plane magnetization measurement performed at various temperatures shows a consistent increase in the coercivity (HC) and exchange bias field (HEB) as the temperature lowered, with a significant increase below 100K. The occurrence of small exchange bias indicates the existence of a non-negligible exchange coupling between the core spins and surface spins of the Fe3O4 grains. The ZFC-FC measurements show that samples are having a wide particle size distribution, along with the existence of stronger interaction between the nearby Fe3O4 grains.