Ad Hoc Determination of Local Misorientations and Boundary Planes between Grains in TEM by a Dedicated Software Package Developed for the Gatan DigitalMicrograph Platform

Mechanical and electrical properties of materials are often highly dependent on the crystallographic direction by which they are measured. For properties being measured over spatially limited extents, grain boundaries (GBs) present in crystals can greatly complicate interpretation of results. It is therefore necessary to characterize GBs in terms of the rotation of a particular vector in one grain to a similar vector in another. In a similar fashion the GB between two crystal grains can have a multitude of possible GB plane configurations. These different GB plane configurations could potentially have a strong correlation with the properties of a crystal system, requiring the precise GB plane configuration to be determined for accurate interpretation of results. Understanding these geometric parameters defining the boundary between grains is essential for appropriate analysis of many problems facing a transmission electron microscope (TEM) operator. Often the method of investigation may change depending on the misorientaiton of two grains or the particular GB plane encountered by the microscopist during a microscope session. To expedite the process of TEM investigation involving individual GBs a method of determining a full geometric description of a GB during a microscopy session is desirable (ideally on-th-fly measurements). This project presents the creation of a software package for the Gatan Digital Micrograph platform that provides simple ad hoc determination of the misorientation and GB plane normal vector of a GB with minimal input from the microscopist.