Ordered Surface Alloy of Bulk-Immiscible Components Stabilized by Magnetism
Résumé
Using scanning tunneling microscopy and a diffraction experiment, we have discovered a new ordered surface alloy made out of two bulk-immiscible components, Fe and Au, deposited on a Ru(0001) substrate. In such a system, substrate-mediated strain interactions are believed to provide the main driving force for mixing. However, spin-polarized ab initio calculations show that the most stable structures are always the ones with the highest magnetic moment per Fe atom and not the ones minimizing the surface stress, in remarkable agreement with the observations. This opens up novel possibilities for creating materials with unique properties of relevance to device applications.