Structure Related Magnetic Dead Layer for Ultrathin Fe/Ir(111) Films

Magnetic properties and surface structure of ultrathin Fe/Ir(111) films have been investigated using the surface magneto-optic Kerr effect and low-energy electron diffraction. Layer-by-layer growth of Fe/Ir(111) is observed for the first three monolayers at room temperature. For Fe thinner than three monolayers, pseudomorphic growth of Fe films is observed. The layer distance is close to that of fcc(111) Fe. For Fe thicker than three monolayers, the surface structure can be identified to be related to the bcc(110) arrangement of Fe atoms in Kurdjumov-Sachs orientation. As the Fe thickness increases, the linear increase of the Kerr intensity is observed. The Kerr intensity comes from the bcc-Fe and a thin magnetic dead layer is observed at the interface.