BiSbWO6: Properties of a mixed 5s/6s lone-pair-electron system

Abstract

• Stereochemical activity of lone-pair electrons as an alloy-design principle. • BiSbWO 6 alloys share narrow thermodynamic stability range. • Sb/Bi lone-pair effects on electronic structure identified and decoupled. • WO 3 used as a control model to isolate role of mixed lone-pair electrons. • Local distortions due to Sb 5s lone-pair electrons upshift conduction band edges. We investigate the behavior of lone-pair electrons in a mixed Sb(5s)/Bi(6s) crystal-environment. Density functional theory is used to calculate the electronic properties of Sb-alloyed-Bi 2 WO 6 and to study the effects of introducing Sb 5s orbitals to the band structure. The band edge positions, partial charge analyses, and band decomposed charge densities of BiSbWO 6 are used to explain the observed trends in relative stabilities and band edge shifts. To isolate the role of the mixed lone-pair, we considered WO 3 as a control model. We find that local distortions caused by Sb 5s lone-pair electrons lead to upshifts in both valence and conduction band edges.