Microstructure of epitaxial alpha-Fe2O3 grains in Ba-ferrite thin films grown on sapphire (001)

Abstract

We revealed the existence of epitaxial alpha-Fe2O3 grains in Ba-ferrite thin films on sapphire (001) using synchrotron x-ray scattering. The antiferromagnetic alpha-Fe2O3 grains were formed during the crystallization of amorphous Ba-ferrite films grown on sapphire (001) by radio frequency sputtering deposition. The crystal domain size of the alpha-Fe2O3 grains was about 250 Angstrom in the film plane, similar to that of the Ba-ferrite grains. The in-plane crystalline axis of the alpha-Fe2O3 was aligned to that of sapphire, while the Ba-ferrite film was rotated by 30 degrees in the film plane. We confirm that the existence of these antiferromagnetic alpha-Fe2O3 grains greatly degraded magnetic properties of the Ba-ferrite films. (C) 1999 American Institute of Physics. [S0003-6951(99)03414-2].