Oscillatory decay of magnetization induced by domain-wall stray fields

The demagnetization of a hard ferromagnetic layer via the fringing fields o f domain walls created by reversing the moment of a neighboring soft ferrom agnetic layer is explored experimentally An unusual oscillatory decay of th e magnetic moment of the hard layer is observed using structures in which t he demagnetization occurs after a few hundred cycles. This surprising obser vation is confirmed on a microscopic scale by detailed imaging of the magne tization of the hard layer using high resolution photoemission electron mic roscopy and by micromagnetic simulations.