INTERLAYER THICKNESS DEPENDENCE OF THE STRONG 90-DEGREES COUPLING IN EPITAXIAL COFE MN/COFE TRILAYERS/

Trilayers of CoFe/Mn/CoFe(001) have been prepared by molecular beam ep itaxy and their magnetic properties measured by magnetometry and ferro magnetic resonance. Very strong near-90 degrees coupling between the C oFe layers, with no evidence for 180 degrees coupling, was found in al l but the thickest Mn-Iayer samples. The coupling energy has the form suggested recently for the case when the interlayer itself is antiferr omagnetic. An analysis of the ferromagnetic resonance data indicates t hat the magnitude of the coupling oscillates with the Mn thickness. (C ) 1996 American Institute of Physics.