Atomic scale mechanism of the transformation of γ-alumina to θ-alumina -: art. no. 235501

被引：50

作者：

Cai, SH ^{[1
]}

Rashkeev, SN

Pantelides, ST

Sohlberg, K

机构：

[1] Xiamen Univ, Dept Phys, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China

[2] Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA

[3] Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA

[4] Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA

来源：

PHYSICAL REVIEW LETTERS | 2002年 / 89卷 / 23期

关键词：

D O I：

10.1103/PhysRevLett.89.235501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

gamma-alumina is known to transform to theta-alumina and finally to alpha-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 gamma- to theta-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 theta-alumina. The estimated temperature dependence of the conversion rate is in excellent agreement with the experimental transformation temperature.

引用

页数：4

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