Fabrication and micromagnetic modeling of barium hexaferrite thin films by RF magnetron sputtering

The synthesis and characterization of thin M-type barium hexaferrite (BaFe12O19 or BaM) films on silicon are reported. Multilayer in situ technique was employed to anneal the films at 850-900 °C for 10 min. The thickness dependence of the magnetic properties of the BaM films has been investigated using VSM. For the BaM 150 nm thickness film, acicular BaM grains were present having their c-axis randomly oriented. For the BaM films thicker than 150 nm, lattice relaxation favors the c-axis to be aligned in the film plane. The micromagnetic simulation was used to model the out-of-plane and the in-plane hysteresis loops. We have achieved good matching between the experimental data and the model. Using the micromagnetic model, we have estimated the deflection angle of c-axis from the normal plane θ = 25° for the 150 nm thick film.