PREPARATION OF Ba FERRITE FILM WITH WELL c-AXlS ORIENTATION USING Pt UNDERLAYER

抄録

  Ba ferrite/Pt bilayered films were deposited on thermally oxidized Si wafers using plasma-free sputtering apparatus and post-annealed at 800°C in air for 15 min, and then, the dependence of crystallographical and magnetic characteristics at the substrate temperature T_s in the range from room temperature to 550°C were investigated. Although Ba ferrite films deposited directly on the substrates revealed random c-axis orientation, the Ba ferrite layer deposited on Pt underlayer at T_s above 200°C and post-annealed revealed excellent c-axis orientation. They exhibited the saturation magnetization 4πM_s of 4.2 kG and almost same in-plane and perpendicular coercivity H_c|| and H_c⊥ of 0.7 kOe. The film deposited at T_s above 500°C exhibited 4πM_s of 4.6 kG and high H_c⊥ of 1.8 kOe.