MAGNETIC-MOMENTS, COUPLING, AND INTERFACE INTERDIFFUSION IN FE V(001)SUPERLATTICES/

Epitaxial Fe/V(001) multilayers are studied both experimentally and by theoretical calculations. Sputter-deposited epitaxial films are chara cterized by x-ray diffraction, magneto-optical Kerr effect, and x-ray magnetic circular dichroism. These results are compared with first-pri nciples calculations modeling different amounts of interface interdiff usion. The exchange coupling across the V layers is observed to oscill ate, with antiferromagnetic peaks near the V layer thicknesses t(v) ap proximate to 22, 32, and 42 Angstrom. For all films including superlat tices and alloys, the average V magnetic moment is antiparallel to tha t of Fe. The average V moment increases slightly with increasing inter diffusion at the Fe/V interface. Calculations modeling mixed interface layers and measurements indicate that all V atoms are aligned with on e another for t(v) less than or equal to 15 Angstrom, although the mag nitude of the V moment decays toward the center of the layer. This ''t ransient ferromagnetic'' state arises from direct (d-d) exchange coupl ing between V atoms in the layer. It is argued that the transient ferr omagnetism suppresses the first antiferromagnetic coupling peak betwee n Fe layers, expected to occur at t(v) approximate to 12 Angstrom.