Efficacy of a FIB and Planar Preparation Technique for Producing TEM Lamella of CLS

An unconventional method for creating transmission electron microscopy (TEM) lamella via focused-ion beam (FIB) was evaluated. While the conventional method involves using the FIB to mill and extract a lamella normal to a materials surface, the method tested here involves extracting a lamella in plane with the surface. The benefits of using the unconventional, or planar, method and when it might be used are contrasted with the conventional method. As an example, a TEM-quality lamella is made from a cut and polished bulk sample of calcium lanthanum sulfide using the planar method. Details of the method and parameters used in the procedure, as well as TEM analysis, are discussed.