In situ experiments in the transmission electron microscope

Abstract

Reviews the principles and practice of in situ experimentation in both conventional 100 kV microscopes and those operating at a higher accelerating potential, to provide a practical guide to the electron microscopist. The introductory sections deal with the important question of selecting the optimum image recording technique for the process being studied, and a discussion of the factors that can affect the validity of in situ observations. A description of the design and construction of in situ stages follows and serves to highlight the ingenuity of stage designers faced with the problem of providing services to the specimen in the restricted pole-piece gap region of a microscope without compromising microscope performance. Discussion is confined to the four main types of stages fulfilling the functions of heating and cooling, deformation, environmental control and Lorentz imaging. The experimental application of in situ techniques forms the major part of this review. Emphasis has been placed on investigations producing results which could not have been obtained using other techniques. This section illustrates the unique nature of the information that can be obtained both at the qualitative and quantitative level by in situ experimentation.