First-principles study of defect formation energies in LaO$X$S$_2$ ($X=$ Sb, Bi)

Masayuki Ochi; Kazuhiko Kuroki

doi:10.1103/PhysRevB.105.094110

paper

First-principles study of defect formation energies in LaO $X$ S $_{2}$ ( $X =$ Sb, Bi)

arXiv:2110.12593 · doi:10.1103/PhysRevB.105.094110

Abstract

We theoretically investigate defect formation energies in LaO $X$ S $_{2}$ ( $X =$ Sb, Bi) using first-principles calculation. We find that the oxygen vacancy is relatively stable, where its formation energy is higher in $X =$ Sb than in $X =$ Bi. An interesting feature of $X =$ Sb is that the vacancy of the in-plane sulfur atom becomes more stable than in $X =$ Bi, caused by the formation of an Sb $_{2}$ dimer and the electron occupation of the impurity energy levels. The formation energies of cation defects and anion-cation antisite defects are positive for the chemical equilibrium condition used in this study. Fluorine likely replaces oxygen, and its defect formation energy is negative for both $X =$ Sb and Bi, while that for $X =$ Sb is much higher than $X =$ Bi. Our study clarifies the stability of several point defects and suggests that the in-plane structural instability is enhanced in $X =$ Sb, which seems to affect a structural change caused by some in-plane point defects.

15 pages, 15 figures

First-principles study of defect formation energies in LaOXS2​ (X= Sb, Bi)

Abstract

References in corpus (6)

First-principles study of defect formation energies in LaO $X$ S $_{2}$ ( $X =$ Sb, Bi)