Epitaxial Co80Pt20 films with in-plane uniaxial anisotropy

Uniaxial Co80Pt20 epitaxial films with in-plane anisotropy were prepared by dc sputter deposition using W/Ag templates on H-terminated Si(110) substra tes. The epitaxial relationship as a function of the CoPt thickness, studie d by electron and X-ray diffraction, is complex for CoPt thickness < 5 nm. For CoPt thickness > 5 nm, the epitaxial relationship was found to be CoPt( 10 (1) over bar0)[0001] parallel to W(112)[1 (1) over bar0] parallel to Ag( 110)[001] parallel to Si(110)[001]. Anisotropy constants were measured usin g in-plane torque curves and the initial magnetization curves along the har d axis. For 10 to 20 mn thick Co80Pt20, K-1 was found to be similar to 9 x 10(6) erg/cc and K-2 was negligible.