Experimental studies of the electronic structure of I–II and I–III intermetallic compounds with B32 (Zintl) structure

Abstract

Photoemission and electron energy‐loss data are reported for a series of I–II and I–III intermetallic compounds with B32 (Zintl) structure (LiAl, LiGa, LiIn, and LiZn). The structure of the valence band of LiAl, LiGa, and LiIn agrees well with theoretical relativistic augmented plane‐wave (RAPW) band‐structure calculations, while LiZn deviates appreciably from theory. Binding in Zintl phases is confirmed to be achieved through s‐to‐p charge promotion at both Li and the second metal, rather than by Li–Me(II, III) charge transfer. The rich near‐edge x‐ray absorption fine structure at the Li‐1s absorption edge, and an interband transition observed in electron‐energy loss spectra also support the RAPW predictions for the structure of the empty band. The plasmon energy in LiAl is equal to that calculated for free electrons, and its value is insignificantly affected by the defect structure of the LiAl lattice.