Enhanced in-plane magnetic anisotropies of ultrathin Pt/Co/PT films

摘要

Pt/Co/Pt sandwich films grown on single-crystla MgO substrates have been found to show an anomalous enhancement of the in-plane magnetic anisotropy for ultrathin Co layers below 1 nm. The in-plane sixfold anisotropy of (111)-oriented films yielded a maximum value of about - 1x10~6 erg/cm~3 for 1 nm thickness, which is two orders of magnitude larger than that of fcc Co. for samples with (100) orientation, in-plan fourfold anisotropy increases with decreasing Co layer thickness, showing a maximum value of +1.9X10~6 erg/cm~3 at a thickness of one monolayer.