Abstract
Amorphous Co-Ti films of about 1 μm in thickness have been prepared by r.f. co-sputtering technique. The coercivity of Co-Ti films is found to depend strongly on the sputtering conditions such as the substrate bias and the argon pressure. Soft magnetic films with the coercivity less than 50 mOe are obtained at the substrate bias Vb of −30∼ −50 V. Through the negative bias, the oxygen content in films decreases from 4at.% (Vb = 0V) to less than 1 at.% (Vb = −30∼ −50 V) and further the columner structure observed in the films at Vb = 0V disappears in those at Vb = −30V.
When the films are annealed in a magnetic field, the coercivity is almost constant up to 400°C, while the uniaxial magnetic anisotropy is induced above 200°C.
