Multiscale dynamics in relaxor ferroelectrics
1 Physics Department and Center for Advanced Materials, Lehigh University - Bethlehem, PA, USA
2 Center for Radiation Detection Materials and Systems, Oak Ridge National Laboratory - Oak Ridge, TN, USA
Received: 23 October 2013
Accepted: 2 January 2014
The multiscale dynamics of complex oxides is illustrated by pairs of mechanical resonances that are excited in the relaxor ferroelectric K1−xLixTaO3 (KLT). These macroscopic resonances are shown to originate in the collective dynamics of piezoelectric polar nanodomains (PNDs) interacting with the surrounding lattice. Their characteristic Fano lineshapes and rapid evolution with temperature reveal the coherent interplay between the piezoelectric oscillations and orientational relaxations of the PNDs at higher temperature and the contribution of heterophase oscillations near the phase transition. A theoretical model is presented, that describes the evolution of the resonances over the entire temperature range. Similar resonances are observed in other relaxors and must therefore be a common characteristics of these systems.
PACS: 77.80.Jk – Relaxor ferroelectrics / 77.22.Gm – Dielectric loss and relaxation / 46.40.Ff – Resonance, damping, and dynamic stability
© EPLA, 2013