EvidenceforaMagnetic ProximityEffect uptoRoomTemperatureatFe=ðGa;MnÞAsInterfaces

We report x-ray magnetic circular dichroism and superconducting quantum interference device magnetometry experiments to study magnetic order and coupling in thin Fe=ðGa;MnÞAsð100Þ films. We observe induced magnetic order in the ðGa;MnÞAs layer that extends over more than 2 nm, even at room temperature. We find spectroscopic evidences of a hybridized d configuration of Mn atoms in Fe=ðGa;MnÞAs, with negligible Mn diffusion and/or MnFe intermixing. We show by experiment as well as by theory that the magnetic moment of the Mn ions couples antiparallel to the moment of the Fe overlayer.