Helmut Zerbst

Improvements in electron microscopy by application of superconductivity

Resolution tests on amorphous carbon foils were carried out in an electron microscope with a superconducting system containing 4 lenses including a shielding lens at 200 kV beam voltage. Due to the mechanical and electrical stability of the system and the absence of contamination of the specimen the highest space frequencies transferred at vertically incident beam were 6 nm-1 corresponding to a resolution of 0.17 nm, a value which approaches the theoretical resolving power of the electron optical system. It should also be feasible to apply such a lens system for microprobe analysis without strongly reducing the theoretical resolution limit, if the construction of the shielding lens is slightly changed.

Superconducting lenses in electron microscopy

Abstract Various types of superconducting electron microscope lenses and lens-systems have been designed and tested in the last ten years. A resolution of 0.4 nm was achieved at several laboratories. Future potentialities for the application of superconducting lenses including microwave lenses, for example, in high voltage electron microscopy are discussed.