Molecular dynamics simulation on mechanical properties of crystalline CoSb3 with nanopores

Mechanical stability is of vital significance in commercial application of thermoelectric materials. The essential mechanical behaviours of a nanoporous skutterudite thermoelectric material have been studied by the molecular dynamics method. The research results reveal that the nanoporous skutterudite is a typical non-linear elastic brittle material, and that the existence of nanopores can remarkably reduce the mechanical properties of the skutterudite. Further research results reveal that the elastic modulus of the nanoporous skutterudite decreases with the growing porosity, and the relationship between the elastic modulus and the porosity can be summarised by an inversely proportional scaling law. The ultimate stress reduces gradually with the decreasing inner nanopore spacing. The fracture strain first decreases and then levels off, which can be attributed to the interplay between the increased porosity and the reduced inner nanopore spacing.