Abstract
CoPt alloys were prepared on Mo seeding layers on Al O (11-20), (1-102), and (1-100) substrates by molecular beam epitaxy. Reflection high energy electron diffraction and X-ray diffraction analysis and polar magnetooptical Kerr effect and extraordinary Hall effect investigations demonstrate a strong correlation between the crystal structure and perpendicular magnetic anisotropy in the alloys. The alloys exhibited distinct crystal structures and chemical ordering for substrate temperatures of 300 and 400 °C. The appearance of the ordered L1 (111) phase enhances the perpendicular magnetic anisotropy and the Kerr rotations.