Ru/FeCoB double layered film with high in-plane magnetic anisotropy field of 500 Oe

摘要

FeCoB layers prepared on Ru underlayer possess a high saturation magnetization M_s and a high in-plane magnetic anisotropy filed H_k. Effects of preparation conditions were investigated. Low Ar gas pressure condition and thicker film thickness were effective to attain distortion of FeCo crystallite. As the crystallinity of Ru underlayer became higher, higher H_k was induced. The accumulation of anisotropic stress in the film caused by the oblique incidences of depositing atoms with high energy seems to be one of the important effects to attain high anisotropy field. It was succeeded to prepare the Ru/FeCoB film with high H_k of 500 Oe.