Oscillating magnetic anisotropy in epitaxial Au/Fe(1 1 0) and Co/Au/Fe(1 1 0) films

We report on the in-plane magnetic anisotropy in Au/Fe(1 1 0) and Co/Au/Fe(1 1 0) bi- and trilayers epitaxially grown on a W(1 1 0) single crystal. Magnetic surface anisotropy (MSA) exhibits a strongly non-monotonic, oscillatory behavior as a function of Au thickness. In the case of the Au/Fe(1 1 0) bilayers bi-periodic oscillations were observed and interpreted in terms of quantum well states that are affected by the alternating complete and in-complete atomic layers of Au. Thin bcc Co films grown on Au/Fe(1 1 0) bilayers strongly enhance MSA and for the Co/Au/Fe system magnetic anisotropy oscillates as a function of the Au spacer thickness due to the oscillatory interlayer coupling.