eV-TEM: transmission electron microscopy with few-eV electrons

Abstract

Electron microscopy has become an extremely important technique

in a wide variety of elds. The resolving power is vastly superior

to light microscopes and electron microscopy has proven to

be valuable in elds ranging from archaeology and geology to biology and condensed-matter physics. A major disadvantage is that the electron energy used in conventional Electron Microscopy (EM) ranges from 10’s to 100’s of keV. Such energetic electrons can signicantly damage the specimen. This is especially relevant in the study of biological samples and organic materials in general. Major eorts are being made to avoid this radiation damage from interfering with the study of such materials. There are several approaches to minimize damage in EM. These include developing better detectors such that lower electron doses are sucient to form an image, and lowering the electron energies to several keV. In this dissertation I present the development of, and measurements with, a transmission electron microscope that uses electron energies ve orders of magnitude lower than in conventional Transmission Electron Microscopes (TEMs). The energies we use are in the order of a few eV. Hence, we call our technique ’eV-TEM’.