抄録
We investigated the indirect exchange coupling between Co and Gd across nonmagnetic interlayers in Co/X/Gd/X multilayers (X=Cu, Ag, Au, Pt, Y, and W). The spin-flop field, Hsf, decrease with increasing interlayer thickness, tx, for all X. However, the manner of the decrease depends strongly on X: For X=Cu, Hsf decreases owing to interdiffusion between Cu and Gd at the interfaces. For X=Ag, Au, Pt, Y, and W, the decrease in Hsf is considered to be due to a decrease in the exchange coupling strength, Jco-Gd. For X= Ag, Au, Pt, and Y, Jco-Gd decreases slowly with increasing tx and remains even for tx≥10Å; for X=W, on the other hand, it decreases repidly and disappears for tx≥5Å. We consider that the difference is attributable to the electronic structure of X.