A series of bcc-Co(001)/Ge/Co trilayers was grown on a GaAs(001) subst
rate by the molecular beam epitaxy technique. The optical and magneto-
optical properties of the samples were studied. An oscillatory variati
on of the magneto-optical Kerr effect (MOKE) with the thickness of the
Ge spacers was observed. We conclude that the effective optical const
ants as well as the real and imaginary off-diagonal element of the die
lectric tensor should be considered in explanation of the MOKE activit
ies since both have a large influence on the MOKE oscillations. Moreov
er, the coercivity and magnetization also oscillate with the Ge layer
thickness. (C) 1996 American Institute of Physics.