Local lattice potentials and steady-state vacancies in ionic crystals

TL;DR

This paper explores how local lattice potentials influence vacancy formation in ionic crystals, revealing two main mechanisms: thermal anion vacancies in semiconductors and cation vacancies in certain compounds.

Contribution

It identifies two principal trends in vacancy formation driven by local potential effects, linking electronic delocalization and potential field equalization to vacancy types.

Findings

Giant potential contributions lead to thermal anion vacancies in semiconductors.

Potential field equalization results in high cation vacancy concentrations.

Different vacancy formation mechanisms are linked to local potential characteristics.

Abstract

Basing on peculiarities of local potentials, the two principal trends in vacancy formation are revealed. The proximity to the threshold of local ionic stability due to a giant potential contribution of electronic delocalization accounts for thermal anion vacancies typical of intrinsic semiconductors of AB type. On the other hand, the tendency towards equalizing the potential field results in a high concentration of structural cation vacancies observed in Ni_3 Sb and relative compounds.