Magnetic dead layers in Fe films induced by a lattice mismatch at an interface

The magnetism of Fe thin films grown at room temperature on the Rh(001) surface was studied by angle- and spin-resolved photoemission, X-ray photoelectron diffraction, soft X-ray magnetic circular dichroism (XMCD), and band calculations using full-potential augmented plane wave method. On the Rh(001) surface Fe films start to grow in a FCT(001) structure with a lattice constant compressed along the direction perpendicular to the surface and the compression is gradually released as the film thickness increases. The characteristic growth mode of the Fe films on the Rh(001) surface results in the existence of magnetically dead 2 monolayers (ML) of Fe at the interface and of ferromagnetism over 2 ML, which are realized by the XMCD experiments measured at low temperature. The thickness dependence of the magnetic properties of the Fe films is consistent with the results of total energy calculations adopting the experimentally obtained interlayer spacing.