Unusual compression behavior ofTiO2polymorphs from first principles
| Autor: | Guang-Rui Qian (钱广锐), Lixin Zhang (张立新), Hui-Tian Wang (王慧田), Xiang-Feng Zhou (周向锋), Yonjun Tian (田永君), Xiao Dong (董校) |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Physical Review B. 82 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.82.060102 |
| Popis: | The physical mechanisms behind the reduction in the bulk modulus of a high-pressure cubic ${\text{TiO}}_{2}$ phase are revealed 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 ${\text{TiO}}_{2}$ to a modified fluorite ${\text{TiO}}_{2}$ with a $Pca21$ symmetry. Oxygen atom displacement in $Pca21$ ${\text{TiO}}_{2}$ unexpectedly reduces the bulk modulus by 34% relative to fluorite ${\text{TiO}}_{2}$. This discovering provides a direct evidence for understanding the compressive properties of such groups of homologous materials. |
| Databáze: | OpenAIRE |
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