First-principles calculations were used to investigate the stability, electronic structure, elastic and lattice thermal conductivity of FeS and FeS₂ polymorphs (α-FeS, β-FeS, γ-FeS, α-FeS₂, β-FeS₂). The calculated lattice parameters were in agreement with experimental results. The results showed that these Fe-S binary compounds are thermodynamically and mechanically stable. The elastic anisotropies of Fe-S binary compounds were exhibited by 3D modulus ball and 2D projections. Among all the five compounds, α-FeS₂ compound has the largest bulk modulus and β-FeS₂ has the largest Young’s modulus and hardness. Furthermore, α-FeS, β-FeS and γ-FeS compounds can be regarded as ductile material according to B/G and Poisson’s ratio. The FeS compounds show metallic character and FeS₂ compounds show semiconductor character through analyzing their bandgap and density of states (DOS). The β-FeS₂ has the largest thermal conductivity according to the Clarke model, and the β-FeS shows the strongest thermal conductivity anisotropy among the five compounds.

中文翻译：

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FeS和FeS2多晶型物的稳定性、电子结构、力学性能和晶格热导率

第一性原理计算用于研究FeS和FeS ₂多晶型物的稳定性、电子结构、弹性和晶格热导率（α-FeS,β-FeS,γ-FeS,α-FeS ₂ ,β-FeS ₂ )。计算的晶格参数与实验结果一致。结果表明，这些Fe-S二元化合物在热力学和机械上都是稳定的。Fe-S二元化合物的弹性各向异性通过3D模量球和2D投影表现出来。在所有五种化合物中，α-FeS ₂化合物具有最大的体积模量和β-FeS ₂具有最大的杨氏模量和硬度。此外，α-FeS,β-FeS 和γ-FeS 化合物可被视为延展性材料，根据乙/G和泊松比。通过分析它们的带隙和态密度（DOS），FeS化合物显示出金属特性，而FeS _{2化合物显示出半导体特性。}这β-根据克拉克模型，FeS _{2具有最大的热导率，并且}β-FeS 在五种化合物中表现出最强的热导率各向异性。