Local beam heating in metallic electron microscope specimens

Summary A very sensitive method is described to measure the local rise in the temperature of a metal specimen during investigation in the electron microscope. The method is based on the known temperature dependence of the climb rate of Frank dislocation loops in materials with relatively high stacking fault energy. The climb rate of loops subject to the influence of the condensed electron beam is compared to the corresponding rate for loops in an area of the same specimen which is remote from the observation spot. From the difference in the logarithms of these rates the amount of local beam heating is determined. For a typical Al‐1.5 wt% Mg specimen under typical normal working conditions an average local rise in temperature of approximately 6°C was determined.