Unusual Valence State in the Antiperovskites Sr${}_3$SnO and Sr${}_3$PbO Revealed by X-ray Photoelectron Spectroscopy

D. Huang, H. Nakamura, K. Küster +6

The class of antiperovskite compounds $A_{3}B$O ($A$ = Ca, Sr, Ba; $B$ = Sn, Pb) has attracted interest as a candidate 3D Dirac system with topological surface states protected by cr…