OSCILLATORY EXCHANGE COUPLING IN FE AU/FE(100)/

Scanning electron microscopy with polarization analysis was used to in vestigate the interlayer exchange coupling in Fe/Au/Fe(100) sandwich s tructures. The films were epitaxially grown on single-crystal Fe(100) substrates. Electron diffraction measurements revealed that the Au spa cer film grew with a surface reconstruction consistent with that obser ved for bulk Au crystals. The exchange coupling oscillates between pri marily ferromagnetic and antiferromagnetic coupling for Au spacer laye rs up to 65 layers (13 nm) thick, but a significant biquadratic coupli ng component was also observed. The oscillatory coupling exhibited two components with periods of 2.48+/-0.05 layers (0.506+/-0.010 nm) and 8.6+/-0.3 layers (1.75+/-0.06 nm). The measured periods are in excelle nt agreement with those calculated from spanning vectors of the Au Fer mi surface.