Anomalies in the elastic and inelastic properties of Co$_{x}$(PZT)$_{100-x}$ nanocomposites

The elastic $(G)$ and inelastic $(Q^{-1})$ properties of Co$_{x}$(PZT)$_{100-x}$ nanocomposites ($x$ = 23–76 at %) obtained by ion-beam sputtering have been studied in the temperature range 200–900 K. Internal friction peaks associated with Co atom hopping inside metallic granules have been discovered at 236 K. It has been found that the peak height grows with metallic phase concentration. Above 750 K, curve $Q^{-1}(T)$ rises considerably because of vacancy diffusion in Co granules under conditions of confined space.