Prediction of a Stable Post-Post-Perovskite Structure from First Principles
Abstract
A novel stable crystallographic structure is discovered in a variety of ABO3, ABF3 and A2O3 compounds (including materials of geological relevance, prototypes of multiferroics, exhibiting strong spin-orbit effects, etc...), via the use of first principles. This novel structure appears under hydrostatic pressure, and is the first "post-post-perovskite" phase to be found. It provides a successful solution to experimental puzzles in important systems, and is characterized by one-dimensional chains linked by group of two via edge-sharing oxygen/fluorine octahedra. Such unprecedented organization automatically results in anisotropic elastic properties and new magnetic arrangements. Depending on the system of choice, this post-post-perovskite structure also possesses electronic band gaps ranging from zero to ~ 10 eV being direct or indirect in nature, which emphasizes its "universality" and its potential to have striking, e.g., electrical or transport phenomena.
Cite
@article{arxiv.1410.5030,
title = {Prediction of a Stable Post-Post-Perovskite Structure from First Principles},
author = {Changsong Xu and Bin Xu and Yurong Yang and Huafeng Dong and A. R. Oganov and Shanying Wang and Wenhui Duan and Binglin Gu and L. Bellaiche},
journal= {arXiv preprint arXiv:1410.5030},
year = {2015}
}