Cobalt spin arrangement in Co/Nd multilayers with depth-selectively inserted 57Fe probe layer

Abstract

Magnetic properties of the Co/Nd multilayers with a 2 Å layer of 57Fe evaporated in UHV conditions were studied in the temperature range 4.2 K < T < 300 K by means of VSM magnetometry and Mössbauer spectroscopy. The isomer shift, hyperfine field distribution and its direction were obtained from a Mössbauer data computer fitting. The easy magnetization direction was found close to the sample normal for all samples at low temperatures and there was a stronger tendency to the perpendicular direction for the sample when the probe layer was placed in a close vicinity of the Co/Nd interface. For this sample the out-of-plane easy direction was preserved at 300 K. For all other studied samples, in-plane anisotropy was observed at room temperature.