Epitaxial growth mechanism of L10 FePt thin films on Pt/Cr bilayer with amorphous glass substrate

Ordered L 10 FePt films with magnetic perpendicular anisotropy were fabricated with a PtCr bilayer. The squareness of the L 10 FePt film with a Cr underlayer and a Pt buffer was close to one when a magnetic field was applied perpendicular to the film's plane, because a semicoherent epitaxial growth was initiated from the Cr (002) underlayer; continued through the Pt buffer layer, and extended into the L 10 FePt (001) magnetic layer. Without the Pt buffer layer, the Cr atoms may diffuse directly into the FePt magnetic layer. Consequently, an epitaxial barrier of the Cr-rich FePtCr alloy formed between the Cr underlayer and the FePt magnetic layer, degrading the magnetic performance and epitaxial growth of the latter. © 2005 American Institute of Physics.