Prediction of Strongly Enhanced Two-Dimensional Ferromagnetic Moments on Metallic Overlayers, Interfaces, and Superlattices

Strongly enhanced two-dimensional ferromagnetic moments are predicted for $3d$ bcc transition metals as overlayers and/or sandwiches and superlattices with Au and Ag. These range (in Bohr magnetons) from (i) 3.70 for Cr/Au(001), 2.96 for Fe/Ag(001), and 2.0 for V/Ag(001) for the overlayers, to (ii) 3.10 for the Au/Cr/Au sandwich and 2.95 for the Cr/Au superlattice, and to (iii) 3.1 for Cr on Fe/Au(001) and 2.30 for Fe on Cr/Ag(001). Surprisingly, a sizable moment (0.14${\mathrm{\mu }}_{\mathrm{B}}$) is induced onto neighboring Au atoms. The noble metals play an optimal role as an almost ideal substrate which allows two-dimensional magnetism to occur.