Specimen preparation of free-standing, thick-metal, multilayered films in cross section

A new preparation method permits the production of large-area, electron-transparent, transmission electron microscopy (TEM) specimens in cross section of free-standing, thick, multilayered structures. Such production often has been difficult in the past because of large chemical differences between the component layers in the multilayer. This difference usually results in a large difference in thinning rates between the layers. A unique combination of electroplating, lapping, dimpling, and low-angle ion milling is a successful and reproducible technique for producing high-quality TEM specimens of these complex materials. Procedures and results presented here are for a 304 stainless-steel/copper multilayer having a repeat period of 20 nm and a total thickness of 20 microns.