Concerning the Preparation of Thin Foils for the Transmission Electron Microscope Using Ion Bombardment.

It was found in critical examinations of the results of others and author's experimentation that by thinning a metallic target with ions accelerated in vacuum that a metal foil can be obtained for examination in the transmission electron microscope. However, ion bombardment causes an undesirable etching effect which restricts the selection of specimens suitable for TEM studies. Several reasons for this etching effect are suggested. It was found impossible to suppress the effect, regardless of apparatus and operating conditions used. Copper foil was used in most of the tests.