Ordered ground state wurtzite alloys from zinc-blende parent compounds

Abstract

The ground state structures of the A{sub x}B{sub 1-x}C wurtzite (WZ) alloys with x=0.25, 0.5, and 0.75 are revealed by a ground state search using the valence-force field model and density-functional theory total-energy calculations. It is shown that the ground state WZ alloy always has a lower strain energy and formation enthalpy than the corresponding zinc-blende (ZB) alloy. Therefore, we propose that the WZ phase can be stabilized through alloying. This idea is supported by the fact that the WZ AlP{sub 0.5}Sb{sub 0.5}, AlP{sub 0.75}Sb{sub 0.25}, ZnS{sub 0.5}Te{sub 0.5}, and ZnS{sub 0.75}Te{sub 0.25} alloys in the lowest-energy structures are more stable than the corresponding ZB alloys. In this example, the alloy adopts a structure distinct from both parent phases.