混合ガススパッタによる垂直記録媒体用Baフェライト膜の低温形成

抄録

  Ba ferrite films with well c-axis orientation and magnetic characteristics were deposited on ZnO underlayer at substrate temperature T_s from 475 to 600°C in the gas mixture of Xe 0.10 Pa, Ar 0.08 Pa and O₂ 0.02 Pa using the facing targets sputtering apparatus. The film deposited at T_s of 600°C was composed of BaM ferrite and spinel crystallites and had saturation magnetization 4πM_s of 5.1 kG and perpendicular anisotropy constant K_ul of 4.23×10⁵ J·m^-3 which were larger than those of bulk BaM ferrite of 4.8 kG and 3.30 × 10⁵ J·m^-3, respectively. C-axis orientation was observed even for the film deposited at low T_s of 475°C and its values of 4πM_s, perpendicular coercivity H_c⊥ and in-plane one H_c// were 4.7 kG, 2.38 kOe and 0.19 kOe, respectively.