Annealing effects on the properties of amorphous CoSiB/Pt multilayer films with perpendicular magnetic anisotropy

The perpendicular magnetic anisotropy (PMA) of amorphous CoSiB/Pt multilayer systems was studied as a function of the thickness of the CoSiB/Pt bilayer and the number of repeated CoSiB/Pt bilayers. In this letter, we investigate the thermal property of a CoSiB single layer film annealed at 150 ∼ 350 .deg. C for 3 hours and the perpendicular magnetic anisotropic property of amorphous ferromagnetic Ta(50 A)/Pt(30 A)/[CoSiB(2, 3, 4, 5, 6 A)/Pt(14 A)]5/Ta(50 A) multilayer films annealed at 200 ∼ 400 .deg. C for 3 hours. The thermal properties were measured by using a differential scanning calorimeter and an X-ray diffractometer, and the magnetic properties were measured by using a vibrating sample magnetometer. The PMA of the CoSiB/Pt multilayer film disappeared and the multilayer film show isotropy after annealing at a temperature of 350 .deg. C or above.