Molecular dynamics study of deformation and fracture in SiC with angular dependent potential model

作者：Kubo Atsushi; Nagao Shijo; Umeno Yoshitaka^*

来源：Computational Materials Science, 2017, 139: 89-96.

DOI：10.1016/j.commatsci.2017.07.023

• Molecular dynamics
• Angular dependent potential
• SiC
• Fracture
• Dislocation

An interatomic potential for SiC based on the angular-dependent potential (ADP) model is developed based on reference data obtained by first-principles calculations. The reference data include not only the energy, stress and interatomic forces of equilibrium and strained crystals but also the stress-strain relationship obtained in ideal strength analyses, with the aim to make the potential suitable for simulations of fracture. The constructed potential successfully reproduces the critical stress of the 3C and 4H structures under various loading conditions. Another distinct feature of the developed potential is the inclusion of point charges in the pairwise term, which enables the description of an environment with excess electric charge. Molecular dynamics simulations using the potential demonstrate fracture of thin films, where ductile and brittle fracture behaviors are found depending on crystal orientations and local stress conditions, and dislocation motion under shear stress, where excess electric charge is seen to influence the mobility of C-core and Si-core partial dislocations.

• 出版日期2017-11