Mechanical stability is critically essential in the design of thermoelectric devices.In this study,we employed first-principles calculations based on density functional theory to investigate the failure mechanisms at ...Mechanical stability is critically essential in the design of thermoelectric devices.In this study,we employed first-principles calculations based on density functional theory to investigate the failure mechanisms at the CoSb_(3)/Ni interface.Our findings reveal that the CoSb_(3)(100)/Ni(100)and CoSb_(3)(100)/Ni(111)_1 configurations are favorable interface structures.The ideal tensile strength of the CoSb_(3)/Ni interface is markedly lower than that of bulk CoSb_(3),which can be attributed to structural rearrangements near the interface that weaken the strength of the Co–Sb bonds.Interface failure occurs in CoSb_(3),where covalent Sb–Sb bonds exhibit a tendency to soften prior to the ionic Co–Sb bonds due to their comparatively lower rigidity.Consequently,the breakage of the Co–Sb bonds leads to interface failure.Structural failure at both single-layer Sb_CoSb_(3)(100)/Ni(100)and single-layer Sb_CoSb_(3)(100)/Ni(111)_1 interfaces results from ruptures in intermediate Co–Sb bonds in CoSb_(3),whereas failures at double-layer Sb_CoSb_(3)(100)/Ni(100)and double-layer Sb_CoSb_(3)(100)/Ni(111)_1 interfaces stem from fractures in the uppermost Co–Sb bonds.This behavior is primarily driven by atomic rearrangements near the single-layer Sb_CoSb_(3)interface,which promote bond formation between Sb–Ni and Co–Ni,thereby enhancing stability within the superstructure of CoSb_(3).This study will provide a theoretical basis for the interface design of thermoelectric devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.92163212,92163215,and 92163119)support by Act 211 Government of the Russian Federation,under No.02.A03.21.0011by the Supercomputer Simulation Laboratory of South Ural State University.
文摘Mechanical stability is critically essential in the design of thermoelectric devices.In this study,we employed first-principles calculations based on density functional theory to investigate the failure mechanisms at the CoSb_(3)/Ni interface.Our findings reveal that the CoSb_(3)(100)/Ni(100)and CoSb_(3)(100)/Ni(111)_1 configurations are favorable interface structures.The ideal tensile strength of the CoSb_(3)/Ni interface is markedly lower than that of bulk CoSb_(3),which can be attributed to structural rearrangements near the interface that weaken the strength of the Co–Sb bonds.Interface failure occurs in CoSb_(3),where covalent Sb–Sb bonds exhibit a tendency to soften prior to the ionic Co–Sb bonds due to their comparatively lower rigidity.Consequently,the breakage of the Co–Sb bonds leads to interface failure.Structural failure at both single-layer Sb_CoSb_(3)(100)/Ni(100)and single-layer Sb_CoSb_(3)(100)/Ni(111)_1 interfaces results from ruptures in intermediate Co–Sb bonds in CoSb_(3),whereas failures at double-layer Sb_CoSb_(3)(100)/Ni(100)and double-layer Sb_CoSb_(3)(100)/Ni(111)_1 interfaces stem from fractures in the uppermost Co–Sb bonds.This behavior is primarily driven by atomic rearrangements near the single-layer Sb_CoSb_(3)interface,which promote bond formation between Sb–Ni and Co–Ni,thereby enhancing stability within the superstructure of CoSb_(3).This study will provide a theoretical basis for the interface design of thermoelectric devices.
