Metastable rhombohedral Fe phase formed in Fe/Sb multilayers and its magnetic properties

Abstract

Fe/Sb multilayer films with various Fe and Sb layer thicknesses were prepared by vapor deposition. A metastable rhombohedral Fe phase was formed in the Fe/Sb multilayered films, when the Fe layer thickness was of 1.7 nm and the Sb layer thickness was of 10 nm. In an opposite condition, a metastable bcc Sb phase was obtained, when the Fe layer was thicker than 4 nm and the Sb layer was thinner than 2.5 nm. Interestingly, the metastable rhombohedral Fe exhibited ferromagnetic behavior and its average magnetic moment was as high as $1.52{\ensuremath{\mu}}_{B}.$ The magnetic behavior and electronic and magnetic structures of the rhombohedral Fe were calculated by the first-principles all-electron linearized augmented plane-wave method (LAPW) within the local spin-density functional approximation. The difference between the calculation of the Fe magnetic-moment amplitude $(3.32{\ensuremath{\mu}}_{B})$ and the experimental determination $(1.52{\ensuremath{\mu}}_{B})$ was discussed in terms of the presence of dead layers at the Fe/Sb interfaces.