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Effects of Pressure on Structural, Mechanical, and Electronic Properties and Stability of Fe x Si y Compounds
Author(s) -
Wang Gao-Min,
Zeng Wei,
Xu Xia,
Liu Wei-Hong,
Tang Bin,
Fan Dai-He,
Liu Qi-Jun,
Chang Xiang-Hui,
Zhong Mi
Publication year - 2020
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.202000083
Subject(s) - materials science , lattice constant , brittleness , structural stability , high pressure , lattice (music) , deformation (meteorology) , thermodynamics , crystallography , composite material , diffraction , chemistry , structural engineering , engineering , physics , acoustics , optics
Herein, the pressure dependence of the structural, mechanical, and electronic properties is investigated for Fe 2 Si, FeSi, Fe 3 Si, α‐FeSi 2 , β‐FeSi 2 , Fe 5 Si 3 , and Fe 11 Si 5 in the pressure range of 0–100 GPa based on density functional theory. The calculated lattice constants are in good agreement with the experimental results. The order of the thermodynamic stability of the seven structures is FeSi > Fe 5 Si 3 > Fe 2 Si > β‐FeSi 2 > Fe 11 Si 5 > α‐FeSi 2 > Fe 3 Si. The electronic properties are analyzed including density of states and band structures. The mechanical properties of FeSi, Fe 2 Si, Fe 5 Si 3 , α‐FeSi 2 , and β‐FeSi 2 are studied thoroughly: The elastic constants are obtained under different pressures; the mechanical stability under the considered pressures is evaluated by the stability criteria. The results show that FeSi, Fe 5 Si 3 , and β‐FeSi 2 are mechanically stable at pressures from 0 to 100 GPa; Fe 2 Si is unstable under compression; and α‐FeSi 2 is unstable in the range of 60–100 GPa. The values of B , G , and E are calculated, which indicate that the ability to resist deformation of the material increases with the increase in pressure. The B / G values are calculated, suggesting that both Fe 5 Si 3 and Fe 2 Si are ductile materials; the brittle–tough transition is observed in FeSi, α‐FeSi 2 , and β‐FeSi 2 .