Formation of the solid solutions in the Au-Ni film system: In situ TEM study

The kinetics of formation of solid solutions in the layered Au (30 at %)-Ni film system of a total thickness of 140 nm during in situ heating in a PEM-125 K transmission electron microscope is studied. Film samples are prepared in a vacuum of 1 x 10(-7) Torr by electron-beam evaporation of the components from independent sources. The state of the system is detected with fast electron diffraction in the temperature range 20-850A degrees C, and the solid solution compositions are calculated with Vegard's law. The experimental results are used to plot the curve that bounds the two-phase solid-state field in the corresponding phase diagram over the entire concentration range. The obtained experimental results are shown to agree well with the reported data. The nickel- and gold-based solid solutions are found to form in heating of the layered Au-Ni film system almost instantly over the entire layer thickness.