Hexagonal Perovskites as Quantum Materials

TL;DR

Hexagonal oxide perovskites, with their unique face-sharing octahedral structures, exhibit intriguing magnetic properties and potential for quantum spin liquid states, making them promising candidates for new quantum materials.

Contribution

This review highlights the solid state chemistry and quantum material potential of hexagonal oxide perovskites, emphasizing their structural features and magnetic properties.

Findings

Potential to host quantum spin liquid states

Distinct magnetic behaviors due to face-sharing octahedra

Structural diversity enabling quantum phenomena

Abstract

Hexagonal oxide perovskites, in contrast to the more familiar perovskites, allow for face-sharing of metal-oxygen octahedra or trigonal prisms within their structural frameworks. This results in dimers, trimers, tetramers, or longer fragments of chains of face-sharing octahedra in the crystal structures, and consequently in much shorter metal-metal distances and lower metal-oxygen-metal bond angles than are seen in the more familiar perovskites. The presence of the face-sharing octahedra can have a dramatic impact on magnetic properties of these compounds, and dimer-based materials, in particular, have been the subjects of many quantum-materials-directed studies in materials physics. Hexagonal oxide perovskites are of contemporary interest due to their potential for geometrical frustration of the ordering of magnetic moments or orbital occupancies at low temperatures, which is especially relevant to their significance as quantum materials. As such, several hexagonal oxide perovskites have been identified as potential candidates for hosting the quantum spin liquid state at low temperatures. In our view, hexagonal oxide perovskites are fertile ground for finding new quantum materials. This review briefly describes the solid state chemistry of many of these materials.