The growth of voids in nickel in a high-voltage electron microscope

Abstract Thin foils of nickel have been electron-irradiated with the beam of a high-voltage electron microscope. In specimens previously ion-bombarded, voids are observed to grow at temperatures between 280°C and 480°C. The results are compared with those for neutron irradiation and are found to be basically similar. Differences are a sharp cut-off at high temperatures, thought to be a thin foil effect, and a much lower proportion of vacancies joining voids in the electron irradiation case. The voids are usually cubes, often elongated, with (100) faces. The size distribution fits a negative exponential function.