INTERNAL-FRICTION AND ITS THERMAL EVOLUTION MEASURED ON VERY THIN PLATINUM FILMS

Internal friction has been measured between 300 and 800 K on thin platinum films using a vibrating reed device. The 575 and 1500 Å thick samples were deposited with ion assistance on silicon substrate. It has been shown that the damping level is considerably reduced by annealing between 650 and 800 K. Thanks to isothermal experiments, we have determined the activation enthalpy of the process involved in the present structural evolution. The calculated energies and complementary transmission electron microscopy micrographs let us assume that the observed mechanism is closely related to microstructural rearrangements located at grain boundaries. © 1995 American Institute of Physics.