Abstract
-alumina is known to transform to -alumina and finally to -alumina upon thermal treatment with a catastrophic loss of porosity and catalytic activity. First-principles calculations were performed to investigate the atomic scale mechanism of the - to -alumina transformation. The transformation pathways between the two different forms have been mapped out and identified as a sequence of Al cation migrations. Different possible Al migration paths may be responsible for the experimentally observed formation of domains and twins in -alumina. The estimated temperature dependence of the conversion rate is in excellent agreement with the experimental transformation temperature.
- Received 17 April 2002
DOI:https://doi.org/10.1103/PhysRevLett.89.235501
©2002 American Physical Society