Theoretical investigations on the structural stability and miscibility in BAlN and BGaN alloys: bond-order interatomic potential calculations

Abstract

Structural stability and miscibility of BxAl1−xN and BxGa1−xN alloys including 3-fold coordinated hexagonal (Hex), 4-fold coordinated wurtzite (WZ) and zinc blende (ZB) structures are systematically investigated based on empirical bond-order potential (BOP), which incorporates electrostatic energies due to bond and ionic charges. We find that the Hex structure is stabilized for free-standing BxAl1−xN and BxGa1−xN alloys with boron composition while the ZB (WZ) structure is stabilized for () both in BxAl1−xN and BxGa1−xN alloys due to the electrostatic energy. Furthermore, the miscibility of BxAl1−xN and BxGa1−xN alloys with 4-fold coordinated structures are found to be higher than that with Hex structure owing to the chemical energy contribution to the excess energy. These results suggest that our empirical interatomic potentials approach is feasible to clarify structural stability not only for the 3-fold coordinated Hex structure but also 4-fold coordinated WZ and ZB structures in BxAl1−xN and BxGa1−xN alloys.