Prediction of new thermodynamically stable aluminum oxides

Author(s)
Yue Liu, Artem R. Oganov, Shengnan Wang, Qiang Zhu, Xiao Dong, Georg Kresse
Abstract

Recently, it has been shown that under pressure, unexpected and counterintuitive chemical compounds become stable. Laser shock experiments (A. Rode, unpublished) on alumina (Al2O3) have shown non-equilibrium decomposition of alumina with the formation of free Al and a mysterious transparent phase. Inspired by these observations, we have explored the possibility of the formation of new chemical compounds in the system Al-O. Using the variable-composition structure prediction algorithm USPEX, in addition to the well-known Al2O3, we have found two extraordinary compounds Al4O7 and AlO2 to be thermodynamically stable in the pressure ranges 330-443 GPa and above 332 GPa, respectively. Both of these compounds at the same time contain oxide O2- and peroxide O-2(2-) ions, and both are insulating. Peroxo-groups are responsible for gap states, which significantly reduce the electronic band gap of both Al4O7 and AlO2.

Organisation(s)
Computational Materials Physics
External organisation(s)
Moscow Institute of Physics and Technology, Nankai University, State University of New York, Stony Brook, Northwestern Polytechnical University
Journal
Scientific Reports
Volume
5
No. of pages
6
ISSN
2045-2322
DOI
https://doi.org/10.1038/srep09518
Publication date
04-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103009 Solid state physics, 103015 Condensed matter, 103025 Quantum mechanics, 103036 Theoretical physics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/2ff3e9c9-ec9e-4d36-ac00-5cd5441b5f35