Automated extraction of interfacial dislocations and disconnections from atomistic data

We introduce Interfacial Line Defect Analysis (ILDA), a method for identifying and extracting interfacial dislocations and disconnections with little-to-no input from the user on the nature of the interface. By simply providing the orientations and coherency strains for the crystals in a coherent reference state of the interface, ILDA provides exact Burgers vectors. Alternatively, these orientations and strains can be estimated using local atomic deformation gradients, making ILDA fully automated and providing estimated Burgers vectors. ILDA also determines the step height associated with each defect line segment, in case the associated defect is a disconnection. The heart of the method is the identification of atoms residing at co-incidence sites between the two crystals and the construction of a surface mesh connecting these sites that is used to compose Burgers circuits and insert defect line segments. We demonstrate the performance of ILDA in two test cases: a twist grain boundary and a phase boundary.

Automated summary

We present a method called Interfacial Line Defect Analysis (ILDA) for identifying and extracting interfacial dislocations and disconnections without requiring detailed input on the nature of the interface. ILDA can provide exact Burgers vectors by only providing the orientations and coherency strains of the crystals at a coherent reference state of the interface. Alternatively, these orientations and strains can be estimated using local atomic deformation gradients, making ILDA fully automated and providing estimated Burgers vectors. ILDA also determines the step height associated with each defect line segment, in case the associated defect is a disconnection. The method relies on the identification of atoms residing at coincidence sites between the two crystals and the construction of a surface mesh connecting these sites to compose Burgers circuits and insert defect line segments. The performance of ILDA is demonstrated in two test cases: a twist grain boundary and a phase boundary.