Anelastic effects in (AgI)x(Ag2O·B2O3)1?x superionic glasses

We present here the first measurements of acoustic absorption in (AgI)_x(Ag₂O·B₂O₃)_1?x superionic glasses at ultrasonic frequencies (5–45 MHz) and in the 80–434 K temperature range. The attenuation shows, at decreasing temperature, an unusually high peak which seems to be attributed to a thermally activated relaxation process. A possible microscopic explanation of this anomaly is proposed, in connection with the presence of mobile ions in those materials.