Enhanced perpendicular magnetic anisotropy of sputtered Pr-Fe-B thin film by inter-layer diffusion Fe-Si layer

The Pr-Fe-B thin films with c-axis texture deposited on glass substrate with Si3N4 underlayer were prepared by RF magnetron sputtering technique in high vacuum chamber and in-situ heat treatment. The effects of the magnetic layer thickness as well as in-situ heat treatment on the microstructure and magnetic properties of the Pr-Fe-B films with perpendicular magnetic anisotropy (PMA) were investigated. The PMA and coercivity were studied as the function of thickness varying from 50 to 500 nm, and at the annealing temperatures ranging from 500 to 700 degrees C. The results showed that the PMA and coercivity were better at the magnetic layer thickness of 125 nm and in the annealing temperature of 650 degrees C. With this compatible thickness and in-situ heat treatment, the formation of Fe3Si layer by effective inter-diffusion of the main magnetic layer and underlayer supported significantly the Pr2Fe14B phase as well as the PMA strength. The higher coercivity was achieved at 7.5 kOe. The surface morphology was more blossom like. XPS analysis exhibited the distribution of the main magnetic elements that strongly affected by the heat energy at the same thickness through the elemental depth profile.