First-principles thermoelasticity and stability of pyrite-type FeO 2 under high pressure and temperature
| Autor: | Ling-Cang Cai, Zhao Jianzhou, Xiu-Lu Zhang, Mei Tang, Zhen-Wei Niu |
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| Rok vydání: | 2017 |
| Předmět: |
Bulk modulus
Chemistry Mechanical Engineering Metals and Alloys Mineralogy Boundary (topology) Thermodynamics Type (model theory) engineering.material 010502 geochemistry & geophysics 01 natural sciences Stability (probability) Shear modulus Lattice constant Mechanics of Materials Structural stability 0103 physical sciences Materials Chemistry engineering Pyrite 010306 general physics 0105 earth and related environmental sciences |
| Zdroj: | Journal of Alloys and Compounds. 719:42-46 |
| ISSN: | 0925-8388 |
| Popis: | The pyrite-type FeO2 was proposed recently as a new structure that exists in the deep Earth. Taking into account the influence of temperature, we investigated the stability and elastic properties of pyrite-type FeO2 under high pressure. The obtained lattice constants and bulk modulus agree well with the available experimental and theoretical data. We found the stability of pyrite-type FeO2 is greatly affected by temperature and pressure. For example, pyrite-type FeO2 is predicted to be both mechanically and thermodynamically unstable when temperature is beyond 1700 K at 300 GPa. The stable boundary of pyrite-type FeO2 is obtained at high pressure and temperature. Furthermore, the pressure dependences of elastic properties of pyrite-type FeO2 are investigated for the first time. It is found that the values of C44 and shear modulus G are nearly invariable with the increasing pressure and temperature. |
| Databáze: | OpenAIRE |
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