Synthesis and characterization of thin Ba-M hexagonal ferrite films

It is demonstrated that Ba-M hexagonal ferrite films with a thickness of ～100 nm and the properties required for the data recording at a superhigh density can be synthesized on an amorphous substrate. The films are obtained on SiO₂/Si substrates by magnetron sputtering of a Ba-M ferrite ceramic target in a gas mixture of Ar and O₂ taken at the partial pressures of 3.5 and 0.5 mTorr, respectively. In order to obtain the required crystal and magnetic structure, the films were annealed for 1 h at 700, 800, or 900°C. The experimental data show that the annealing at 800°C leads to crystallization of the amorphous deposit into a hexagonal ferrite of the Ba-M type.