Ferromagnetism of Imperfect Ultrathin Ru and Rh Films on a Ag(001) Substrate

Abstract
We present a systematic study of the influence of various types of structural imperfections on the magnetic properties of ultrathin transition-metal films on noble-metal substrates. As a case study, we show by means of ab initio electronic structure calculations that recently predicted ferromagnetism of perfect Ru and Rh monolayers on a Ag(001) substrate is highly sensitive to noninteger coverage by additional Ru or Rh atoms and overlayer-substrate interdiffusion. Both types of structural imperfections strongly reduce the local magnetic moments and lead, in some cases, to a complete extinction of the ferromagnetic state.