Magnetization of ultrathin Fe films deposited on Gd (0001)

Abstract

The magnetization of ultrathin (1.5–6 ML) Fe films deposited on Gd (0001) was studied using spin polarized secondary electron emission spectroscopy. An anomalously high Curie temperature (>320 K) was observed for very low coverages of Fe (1.5 ML). The anomalously high Curie temperature results in part from the strong antiferromagnetic exchange interaction between the Fe and Gd at the interface. In addition, a spin reorientation transition of the Fe magnetization from in-plane to perpendicular was observed as the temperature is increased for Fe thickness between 1.5–4 ML. The spin reorientation is attributed to the competition between the perpendicular anisotropy of the Fe overlayer and the exchange interaction with the in-plane Gd bulk magnetization. Therefore the effects of varying the thickness of the Gd and hence the bulk Curie temperature on the spin reorientation transition can be studied.