OSCILLATION OF THE FE AND CO MAGNETIC-MOMENTS AT THE SHARP (1-10)FE CO INTERFACE AND TEMPERATURE-DEPENDENCE OF THE NEAR-INTERFACE MOMENTS/

By means of time differential perturbed angular correlation spectrosco py, we studied the Cd-111 hyperfine fields in molecular beam epitaxy-g rown Fe/Co multilayers on (1-10) GaAs as a function of temperature (90 -570 K). Together with the known fields for Cd in bcc Fe and in bcc Co , we observed 4 sharply defined satellite fields. They have previously been associated with probe positions near a sharp Fe/Co interface. Wh ereas the Cd hyperfine field in Fe and its satellites decrease with te mperature, the satellites on the Co field increase with temperature as the CdCo field does. We determine values for the near interface momen ts by using them as free parameters when fitting the experimental sate llite fields within a semiempirical model for the hyperfine field. At all temperatures, the Fe and Co magnetic moments near the sharp interf ace between bcc Fe and the monoclinically deformed body centered Co os cillate as a function of the layer number over 2 layers in Co and 3 in Fe. The near interface magnetic moments temperature dependence scales to one of atoms in bulk Fe and Co, respectively: in the investigated temperature range, all Fe moments decrease as (1 - A X T-3/2) while th e Co moments are temperature independent. (C) 1997 American Institute of Physics.