INPLANE MAGNETIC-ANISOTROPY OF ULTRATHIN BCC(110) TRANSITION-METAL FILMS

The in-plane and off-plane magnetic anisotropy energies (MAE) of bcc ( 110) transition-metal monolayers and bilayers are determined by calcul ating the spin-orbit coupling effects, the spin-density distribution, and the electronic spectrum self-consistently for each magnetization d irection. The MAE shows a complicated behavior as a function of d-band filling and is very sensitive to film thickness. Alternations of the easy and hard axes between the off-plane and different in-plane direct ions are identified as well as transitions between uniaxial and multia xial MAE surfaces. Remarkably, the in-plane anisotropy is often of the same order of magnitude as the off-plane anisotropy.