Magnetic Properties of Fe Films on Cr(100)

The magnetization behavior of thin (1-5 nm) epitaxial Fe films on Cr(100) is investigated by the magneto-optical Kerr effect. Hysteresis loops show a strong change of the coercive field in a very narrow temperature range around $T=130\mathrm{}$ K, independent of the film thickness. In addition, films below 3 nm thickness exhibit a strongly reduced remanent magnetization in an intermediate temperature range ($T\approx 140-300$ K). An explanation for both effects is based on the interface exchange coupling which connects the intrinsic antiferromagnetic properties of the Cr substrate to the Fe overlayer and therefore modifies its magnetic properties.