Effect of thermal process on magnetic anisotropy in FeCoB soft underlayer

Abstract Relationship between magnetic anisotropy field H k and thermal processes during the preparation has been studied for FeCoB thin films. The FeCoB films deposited on the glass substrates by facing targets sputtering successfully showed strong magnetic anisotropy when the substrate was heated at the substrate temperature T s above 100 °C. Additionally, the lattice spacing of FeCo(1 1 0) in the perpendicular direction was found to decrease depending on the substrate temperature T s . Among various temperature histories, the heating processes with a phase of increasing T s revealed the further improvement of H k . Meanwhile, high H k in the films disappears after the post-deposition annealing at the temperature above 400 °C.