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arXiv · 1004.4321

Unusual Compression Behavior of Columbite TiO2 via First-Principles Calculations

Xiang-Feng Zhou·Xiao Dong·Guang-Rui Qian·Lixin Zhang·Yonjun Tian·Hui-Tian Wang
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Abstract

The physical mechanisms behind the reduction of the bulk modulus of a high-pressure cubic TiO2 phase are confirmed by first-principles calculations. An unusual and abrupt change occurs in the dependence of energy on pressure at 43 GPa, indicating a pressure-induced phase transition from columbite TiO2 to a newly-identified modified fluorite TiO2 with a Pca21 symmetry. Oxygen atom displacement in Pca21 TiO2 unexpectedly reduces the bulk modulus by 34% relative to fluorite TiO2. This discovering provides a direct evidence for understanding the compressive properties of such groups of homologous materials

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Xiang-Feng Zhou, Xiao Dong, Guang-Rui Qian, Lixin Zhang, Yonjun Tian, Hui-Tian Wang. 2010-04-25. Unusual Compression Behavior of Columbite TiO2 via First-Principles Calculations. https://doi.org/10.1103/physrevb.82.060102

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