SHORT-PERIOD OSCILLATION OF THE INTERLAYER EXCHANGE COUPLING IN THE FERROMAGNETIC REGIME IN CO CU/CO(100)/

A unique sample was prepared on a Cu(100) single crystal, consisting o f three Co layers separated by two Cu layers in the form of wedges ori ented perpendicular to each other: Cu(100)/80 angstrom Co/Cu wedge A/3 0 angstrom Co/Cu wedge B/30 angstrom Co/7 angstrom Cu/30 angstrom Au. Position-sensitive magneto-optical Kerr effect measurements along Cu w edge B, at a fixed position on Cu wedge A corresponding to maximum ant iferromagnetic (AF) coupling, enabled us to investigate not only the A F but also the ferromagnetic (F) coupling between the two 30 angstrom Co layers as a function of the Cu thickness. The measurements confirme d both long and short period coupling oscillations in the AF regime, a nd revealed the predicted extension of the short period through the F regime.