Evolution of structure and magnetic properties of sputter-deposited CoPt thin films on MgO(1 1 1) substrates: Formation of the L11 phase

CoPt thin films with a thickness of 50 nm were deposited on MgO(111) substrates by magnetron-sputtering at temperatures ranging from room temperature to 750 °C. A unique phase evolution of A1 (disordered) → L11 → A1 → L10 was clearly identified by performing θ–2θ scans at different ψ angles using a Huber goniometer. The L11 CoPt phase with perpendicular magnetocrystalline anisotropy can be developed at 250 °C, thus making it a promising material for future ultra-high-density magnetic recording media.