The electronic-structure origin of cation disorder in transition-metal oxides

TL;DR

This paper investigates how the electronic structure of transition-metal ions influences cation disorder stability in TM oxides, providing insights for designing materials with desired disorder properties.

Contribution

It identifies a specific electronic-structure effect that impacts the stability of disordered phases, linking electronic configuration to structural energy variations.

Findings

Electronic configuration determines sensitivity to site distortions.

Mechanism explains stability of disordered phases with large ionic radius differences.

Provides guidelines for discovering new disordered TM oxide compositions.

Abstract

Cation disorder is an important design criterion for technologically relevant transition-metal (TM) oxides, such as radiation-tolerant ceramics and Li-ion battery electrodes. In this letter, we use a combination of first-principles calculations, normal mode analysis, and band-structure arguments to pinpoint a specific electronic-structure effect that influences the stability of disordered phases. We find that the electronic configuration of a TM ion determines to which extent the structural energy is affected by site distortions. This mechanism explains the stability of disordered phases with large ionic radius differences and provides a concrete guideline for the discovery of novel disordered compositions.