Electronic structure and magnetism ofUxTh1−xSbas studied by photoemission

Using photoelectron spectroscopy with synchrotron radiation in the $10<~h\nu <~130$ eV range, we have studied the "$5f,6d$" electron states in single crystal ${\mathrm{U}}_x{\mathrm{Th}}_{1-x}\mathrm{Sb}$. We find that uranium has a quasilocalized $5f$ resonant level with essentially a trivalent configuration and does not change valence in the ordered magnetic region $1.0>~x>~0.3$ while thorium contributes $6d$ conduction-band electrons which play an important role in both the electronic and magnetic properties.