Temperature-dependent spin-resolved electronic structure of EuO thin films

The electronic structure of the ferromagnetic semiconductor EuO is investigated by means spin- and angle-resolved photoemission spectroscopy (spin-ARPES) density functional theory. exhibits unique properties hosting both weakly-dispersive nearly fully polarized Eu $4f$ bands, as well O $2p$ levels indirectly exchange-split interaction with nearest neighbors. Our temperature-dependent spin-ARPES data directly demonstrates exchange splitting in its vanishing at Curie temperature. calculations a Hubbard $U$ term reveal complex nature local on oxygen site conduction bands. We discuss mechanisms indirect 2p analyzing orbital-resolved band characters antiferromagnetic phases. directional effects due to spin-orbit coupling are predicted theoretically be significant particular 4f manifold. analysis shape spin-resolved spectra spectral region reveals signatures hybridization $2p$, agreement theoretical predictions. also analyze changes spin-integrated throughout temperature demonstrate they derive from magnetic phase transition sample aging, unavoidable for this highly reactive material.