Magnetic Properties of TbCo/(SiNx/Co)n Films
The Tb32Co68/(SiNx/Co)n films (n = 0~3) were prepared by magnetron sputtering. The magnetic anisotropy of all Tb32Co68/(SiNx/Co)n films are perpendicular to the film plane. It is found that the saturation magnetization (Ms) and perpendicular coercivity (Hc⊥ ) of the Tb32Co68/(SiNx/Co)3 film are 263 emu/cm3 and 3592 Oe, respectively. This film appears to be a promising material as a heat-assisted magnetic recording (HAMR) medium. The cross-sectional high resolution transmission electron microscope (HRTEM) images show that the interface roughness between the (SiNx/Co)n layers and TbCo layer increases as n is increased. The rough surface provides more obstacles and pinning sites that hinder the motion of the domain walls at interface between the (SiNx/Co)n layers and TbCo layer. Therefore, the Hc values are profoundly influenced by the interface roughness.
Alan K.T. Lau, J. Lu, Vijay K. Varadan, F.K. Chang, J.P. Tu and P.M. Lam
G.P. Lin et al., "Magnetic Properties of TbCo/(SiNx/Co)n Films", Advanced Materials Research, Vols. 47-50, pp. 785-788, 2008