Abstract
We examine the thermodynamics of phase separation and ordering in the ternary CaxPb1-xS and SrxPb1-xS systems by density-functional theory combined with a cluster expansion and Monte Carlo simulations. Similar to most other ternary III-V or IV-VI semiconductor alloys, we find that bulk phase separation is thermodynamically preferred for PbS-CaS. However, we predict the surprising existence of stable, ordered ternary compounds in the PbS-SrS system. These phases are previously unreported ordered rocksalt-based compounds: SrPb3S4, SrPbS2, and Sr3PbS4. The stability of these predicted ordered phases is confirmed by transmission electron microscopy observations and band gap measurements. We believe this work paves the way for a combined theory-experiment approach to decipher complex phase relations in multicomponent chalcogenide systems.
Original language | English (US) |
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Pages (from-to) | 1628-1635 |
Number of pages | 8 |
Journal | Journal of the American Chemical Society |
Volume | 136 |
Issue number | 4 |
DOIs | |
State | Published - Jan 29 2014 |
ASJC Scopus subject areas
- General Chemistry
- Biochemistry
- Catalysis
- Colloid and Surface Chemistry