Evidence for a Magnetic Proximity Effect up to Room Temperature at Fe/(Ga,Mn)As Interfaces

Abstract

We report x-ray magnetic circular dichroism and superconducting quantum interference device magnetometry experiments to study magnetic order
and coupling in thin Fe/(Ga,Mn)As(100) films. We observe induced
magnetic order in the (Ga,Mn)As 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/(Ga,Mn)As, 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.