- journal_title：American Mineralogist
- Contributor：Alexandra Friedrich ; Eiken Haussühl ; Reinhard Boehler ; Wolfgang Morgenroth ; Erick A. Juarez-Arellano ; Björn Winkler
- Publisher：Mineralogical Society of America
- Date：2007-
- Format：text/html
- Language：en
- Identifier：10.2138/am.2007.2549
- journal_abbrev：American Mineralogist
- issn：0003-004X
- volume：92
- issue：10
- firstpage：1640
- section：Articles
The crystal structure of diaspore, AlO(OH), has been investigated by in situ single-crystal synchrotron X-ray diffraction at ~50 GPa using the diamond-anvil cell technique. Diaspore is found to retain its structure up to 51.5 GPa at room temperature, which is more than 30 GPa above the transition pressure to δ-AlO(OH) found in quenched high-temperature experiments and derived from density functional theory calculations. The compression is anisotropic and largest for the a axis. This can be explained by the fact that the structural response to pressure is mainly due to the shortening of the hydrogen bond, which is oriented nearly parallel to the a axis. The hydrogen bond becomes significantly more symmetric with pressure up to 50 GPa.