The present paper discusses the interfacial structure and the effect on the
magnetic and magneto-optical properties in TbFeCo/Pt multilayer films, in
contrast with Fe/Pt multilayers. Both the magnetic and magneto-optical prop
erties are well explained when an interfacial region very similar to an Fe-
Pt alloy is assumed. Low angle X-ray diffraction analyses reveal that the F
e-Pt alloy-like interfacial regions are formed mainly on top of TbFeCo laye
rs, but little on Pt layers. w sigma (xy) spectra indicate that polarizatio
n of Pt in the interfacial region is different from that in Fe/Pt multilaye
rs.