Amorphous Oxide Layers on Gold and Nickel Films Observed by Electron Microscopy

Thin films of vapor-deposited nickel and gold, supported only by copper grids, were annealed inside the electron microscope. The microstructures were recorded as a function of temperature. The originally continuous thin films of nickel (150 Å thick) and gold (400 Å thick) form discontinuous islands at temperatures of 700° and 600°C, respectively. The islands of metal are supported by a thin amorphous membrane, in the nickel films identified as NiO, that accounts for the high tensile strengths observed on thin films.