STUDY OF SPRAY DEPOSITED AG2S THIN-LAYERS BY ACOUSTIC MICROSCOPY

Silver sulfide Ag2S thin films have been prepared on pyrex glass subst rates by the spray pyrolysis technique at 250 degrees C. We have analy zed by acoustic microscopy and particularly by acoustic signature V(z) these films with various thickness (0.4-2 mu m). The acoustic signatu re, performed at 50, 130 and 570 MHz allow us to reach elastic propert ies of Ag2S material and specially Young modulus. Its value, of the or der of 180 CPa, is consistent with the relative low linkage of Ag+ in the structure and the character of fast-ion conductor of Ag2S. Besides elastic properties and using MEB and AFM investigations, we have show n that the V(z) signature gives. valuable information about the bulk d efects in the material. Finally, the experimental results have been di scussed related to the dispersion curves of velocity of the first mode of Ag2S/pyrex system.