High-pressure induced phase transition of FeS2: Electronic, mechanical and thermoelectric properties

• Published in: Journal of alloys and compounds 2017-07, Vol.710, p.267-273
• Main Authors: Harran, Ismail, Chen, Yuanzheng, Wang, Hongyan, Li, Hengtao, Li, Yucai, Tao, Li
• Format: Article
• Language: English
• Subjects: Electrical resistivity; Electronics; First principle; Heat transfer; High pressure; Iron; Mathematical analysis; Phase transitions; Pyrite; Structure prediction; Thermal conductivity; Thermoelectric properties; Thermoelectricity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.03.256

Being as the most abundant natural mineral among the iron-based sulphides, iron pyrite (FeS2) has been extensively investigated. These investigations mainly focused on the known marcasite (Pnnm) and pyrite (Pa3¯) phases, due to unknown of high pressure (HP) structural phases of FeS2. Here, we report a theoretical study up to 300 GPa to uncover a brand new monoclinic HP phase of C2/m structure at above 192 GPa. The stable of this structure is evaluated by the thermodynamical, dynamical and mechanical calculations. The C2/m structure is characterized by distorted FeS6 octahedron together with two connected 1D zigzag-like S chains. Analysis of the thermoelectric calculations indicates that the electronic thermal conductivity and electrical conductivity of C2/m structure linearly increasing with increasing temperature. Meanwhile, it is found that the C2/m phase behaves in a ductile manner through the elastic parameters calculations. •A thermodynamically stable C2/m phase of FeS2 is predicted at pressure above 192 GPa.•The FeS6 octahedron C2/m phase connected with 1D zigzag-like S chain.•Its electronic properties showed a good metallic feature.•The electronic thermal and electrical conductivity increase with increasing T.•The C2/m phase exhibits ductile mechanical property.