AG DISSOLUTION KINETICS IN AMORPHOUS GESE5.5 THIN-FILMS FROM INSITU RESISTANCE MEASUREMENTS VERSUS TIME

GeSe5.5 amorphous thin films are evaporated on Ag ribbons deposited on glass substrate. Resistivity measurements of these Ag bands during dissolution are made "in-situ". The kinetics of the dissolution induced by light emitted by the crucible during evaporation is widely influenced by the temperature of the substrate (77 to 300 K). The dissolution rate varies as the ratio of the initial thicknesses of the GeSe5.5 and Ag layers. A model is proposed which takes into account not only Ag dissolution in depth but also the "extremity effect". This spectacular effect has not yet received a clear explanation.