OBSERVATION OF ATOMIC PLACE EXCHANGE IN SUBMONOLAYER HETEROEPITAXIAL FE/AU(001) FILMS

Submonolayer Fe films on a Au(001) surface were found to exhibit atomic place exchanges with Au atoms during room temperature growth by using the angular profile measurement of high-resolution low-energy electron diffraction. The place exchanged atoms result in 2D Au surface islands and Fe subsurface structures. These inverted 2D islands form a structure with a roughly equal island size and spacing in approximately 0.5 monolayer Fe/Au(001) surfaces. The observed mechanism of the atomic place exchange is consistent with recent first-principles calculations for a heteroepitaxial system.