Hydrogen annealing effect on L10 ordering of CoPt thin films

摘要

L1_0-ordered CoPt is one of the next-generation ferromagnetic materials due to its highperpendicular magnetocrystalline anisotropy and high coercivity. The ordered phase is attributed tophase transformation from A1-disordered CoPt by thermal annealing. Rapid thermal annealing (RTA)is considered as a promising annealing technique to induce phase transformation and obtainL1_0-ordered CoPt owing its high heating rate. Considering future applications to spintronic devices,hydrogen annealing is effective to enhance structural and magnetic properties of L1_0-ordered CoPt.Therefore, it is important to study the effect of hydrogen annealing of RTA on L1_0 ordering of CoPt.However, detail studies on the effect on crystal structures of CoPt thin films have not been reported.In this study, we fabricate Co/Pt multilayer thin films on Si/SiO_2 substrates by electron-beamevaporation. These films are subsequently annealed by RTA under a vacuum or an Ar/H_2 atmosphere.Their crystal structures are characterized by grazing incidence X-ray diffraction (GI-XRD) usingsynchrotron radiation at KEK (BL-8B).