  We report valence and conduction band alignments and offsets for
heterojunctions between CdCr2Se4, an n-type ferromagnetic semiconductor, and
the non-magnetic materials Si and GaAs, evaluated using density functional
theory. We explore numerically the impact of different interface features on
the type of band alignment and the magnitude of the offsets. For example, we
find it is energetically favorable to deplete Cr atoms from the layers at the
interface; this also leads to band alignments smaller in magnitude compared to
those obtained for Cr-rich interfaces and ideal for electrical spin-injection
into either Si or Ga-terminated GaAs substrates.
