Spatially homogeneous ferromagnetism below the enhanced Curie temperature in EuO_{1-x} thin films

摘要

We have used low energy implanted muons as a volume sensitive probe of themagnetic properties of EuO_{1-x} thin films. We find that static andhomogeneous magnetic order persists up to the elevated T_C in the doped samplesand the muon signal displays the double dome feature also observed in thesample magnetization. Our results appear incompatible with either the magneticphase separation or bound magnetic polaron descriptions previously suggested toexplain the elevated T_C, but are compatible with an RKKY-like interactionmediating magnetic interactions above 69 K.