First-principles calculations of the structural, elastic and thermodynamic properties of mackinawite (FeS) and pyrite (FeS2)

被引：37

作者：

Wen, Xiangli ^{[1
,2
]}

Liang, Yuxuan ^{[1
,2
]}

Bai, Pengpeng ^{[1
,2
,3
]}

Luo, Bingwei ^{[1
,2
]}

Fang, Teng ^{[1
,2
]}

Yue, Luo ^{[1
,2
]}

An, Teng ^{[1
,2
]}

Song, Weiyu ^{[4
]}

Zheng, Shuqi ^{[1
,2
,4
]}

机构：

[1] China Univ Petr, Beijing Key Lab Failure Corros & Protect Oil Gas, Beijing 102249, Peoples R China

[2] China Univ Petr, Dept Mat Sci & Engn, Beijing 102249, Peoples R China

[3] Tsinghua Univ, State Key Lab Tribol, Beijing 100084, Peoples R China

[4] China Univ Petr, Coll Sci, State Key Lab Heavy Oil, Beijing 102249, Peoples R China

来源：

PHYSICA B-CONDENSED MATTER | 2017年 / 525卷

关键词：

First-principles; Mackinawite (FeS); Pyrite (FeS2); Elastic properties; Thermodynamic properties; DENSITY-FUNCTIONAL THEORY; AQUEOUS HYDROGEN-SULFIDE; CORROSION PRODUCTS; BAND-GAP; IRON PYRITE; PHONON; STEEL; CHEMISTRY; CONSTANTS; MECHANISM;

D O I：

10.1016/j.physb.2017.09.007

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The thermodynamic properties of Fe-S compounds with different crystal structure are very different. In this study, the structural, elastic and thermodynamic properties of mackinawite (FeS) and pyrite (FeS2) were investigated by first-principles calculations. Examination of the electronic density of states shows that mackinawite (FeS) is metallic and that pyrite (FeS2) is a semiconductor with a band gap of E-g = 1.02 eV. Using the stress-strain method, the elastic properties including the bulk modulus and shear modulus were derived from the elastic C-ij data. Density functional perturbation theory (DFPT) calculations within the quasiharmonic approximation (QHA) were used to calculate the thermodynamic properties, and the two Fe-S compounds are found to be dynamically stable. The isothermal bulk modulus, thermal expansion coefficient, heat capacities, Gibbs free energy and entropy of the Fe-S compounds are obtained by first-principles phonon calculations. Furthermore, the temperature of the mackinawite (FeS)-> pyrite (FeS2) phase transition at 0 GPa was predicted. Based on the calculation results, the model for prediction of Fe-S compounds in the Fe-H2S-H2O system was improved.

引用

页码：119 / 126

页数：8

共 57 条

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