The 90° Brillouin scattering experiment has been performed on a Pb(Zn1/3Nb2/3)O3 single crystal. The frequency shift and linewidth of the c33 pure longitudinal acoustic mode and the c44 pure transverse mode show bending anomalies near Tm=397 K, at which the low-frequency dielectric constant ε has a maximum value. In addition to the acoustic modes, a relaxational mode is found in the form of a central peak. The relaxation time τ of the mode has a temperature dependence similar to that of ε and shows a broad peak anomaly around Tm. The temperature dependence of τ can be analyzed by a modified superparaelectric model.

No abstract

No abstract

No abstract

No abstract