Magnetization and structure of ultrathin Fe films

Abstract

The connection between magnetization and structure of ultrathin films is studied at room temperature for the case of Fe films on W(110) by inserting a 2-monolayer-thick growth-modifying Au layer between film and substrate using spin-polarized low-energy electron microscopy and low-energy electron diffraction. Ferromagnetic order with the easy axis pointing in the $[1\overline{1}0]$ direction appears upon percolation at 1.6 monolayers. Shortly thereafter, the easy axis rotates into the [001] direction. With further increasing thickness the magnetization oscillates between the [001] and the $[1\overline{1}0]$ direction with a maximum deviation from the [001] direction at seven monolayers where the magnetic signal has a maximum. The changes in the magnetization are associated with changes in the structure, strain, and morphology that are deduced from the diffraction patterns and which strongly influence the competition between interface anisotropy, magnetoelastic anisotropy, and dipolar surface anisotropy.