Prediction of new thermodynamically stable aluminum oxides

Autor(en)

Yue Liu, Artem R. Oganov, Shengnan Wang, Qiang Zhu, Xiao Dong, Georg Kresse

Abstrakt

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 Laser shock experiments (A. Rode, unpublished) on alumina (Al2O3) have shown non-equilibrium decomposition of alumina with the formation of free Al and a mysterious transparent phase.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(en)

Computergestützte Materialphysik

Externe Organisation(en)

Moscow Institute of Physics and Technology, Nankai University, State University of New York, Stony Brook, Northwestern Polytechnical University

Journal

Scientific Reports

Band

5

Anzahl der Seiten

6

ISSN

2045-2322

DOI

https://doi.org/10.1038/srep09518

Publikationsdatum

04-2015

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2ff3e9c9-ec9e-4d36-ac00-5cd5441b5f35