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. 14₁) 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.