Correlation between the dynamics of polar nanoregions and temperature evolution of central peaks in Pb(Zn1/3Nb2/3)0.91Ti0.09O3 ferroelectric relaxors

摘要

Acoustic properties of Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 have been investigated in a wide temperature range. The sound velocity of acoustic phonons showed a deviation from its high-temperature linear behavior at the Burns temperature TB~730 K. Upon cooling, acoustic properties exhibited significant changes at about 550 K in polarization state and width of the central peak in addition to changes in frequency and damping of acoustic phonons. This finding suggests that, besides TB, another intermediate characteristic temperature exists in the evolution of relaxor dynamics, which might be related to the formation of long-lived polar nanoregions and associated local strain fields.