Acta Metallurgica Sinica (English Letters) ›› 2025, Vol. 38 ›› Issue (5): 793-802.DOI: 10.1007/s40195-025-01830-4

Previous Articles     Next Articles

First Principles Study of CoSb3/Ni Interface Structure and Mechanical Properties

Cuicui Shu1, Pengcheng Zhai1,2, Xiege Huang1, Sergey I. Morozov3, Guodong Li1,2(), Zhiyuan Pan4()   

  1. 1Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology, Wuhan 430070, China
    2State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
    3Department of Computer Simulation and Nanotechnology, South Ural State University, Chelyabinsk 454080, Russia
    4School of Civil Engineering, Wuhan Huaxia Institute of Technology, Wuhan 430223, China

Abstract:

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 CoSb3/Ni interface. Our findings reveal that the CoSb3(100)/Ni(100) and CoSb3(100)/Ni(111)_1 configurations are favorable interface structures. The ideal tensile strength of the CoSb3/Ni interface is markedly lower than that of bulk CoSb3, which can be attributed to structural rearrangements near the interface that weaken the strength of the Co-Sb bonds. Interface failure occurs in CoSb3, 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_CoSb3(100)/Ni(100) and single-layer Sb_CoSb3(100)/Ni(111)_1 interfaces results from ruptures in intermediate Co-Sb bonds in CoSb3, whereas failures at double-layer Sb_CoSb3(100)/Ni(100) and double-layer Sb_CoSb3(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_CoSb3 interface, which promote bond formation between Sb-Ni and Co-Ni, thereby enhancing stability within the superstructure of CoSb3. This study will provide a theoretical basis for the interface design of thermoelectric devices.

Key words: Thermoelectric, Intercfacial structure, Ideal tensile strength, Failure mechanism