The role of random electric fields in relaxors

Abstract

PbZr_{1-x}Ti_xO_3 (PZT) and Pb(Mg_{1/3}Nb_{2/3})_{1-x}Ti_xO_3 (PMN-$x$PT) are complex lead-oxide perovskites that display exceptional piezoelectric properties for pseudorhombohedral compositions near a tetragonal phase boundary. In PZT these compositions are ferroelectrics, but in PMN-xPT they are relaxors because the dielectric permittivity is frequency dependent and exhibits non-Arrhenius behavior. We show that the nanoscale structure unique to PMN-xPT and other lead-oxide perovskite relaxors is absent in PZT and correlates with a greater than 100% enhancement of the longitudinal piezoelectric coefficient in PMN-xPT relative to that in PZT. By comparing dielectric, structural, lattice dynamical, and piezoelectric measurements on PZT and PMN-xPT, two nearly identical compounds that represent weak and strong random electric field limits, we show that quenched (static) random fields establish the relaxor phase and identify the order parameter.

(main article - 7 pages, 4 figures; supplementary information - 3 pages, 3 figures)

References in corpus (5)

• Phase instability induced by polar nanoregions in a relaxor ferroelectric system
• A reassessment of the Burns temperature and its relationship to the diffuse scattering, lattice dynamics, and thermal expansion in the relaxor PMN
• Single Crystal Study of Competing Rhombohedral and Monoclinic Order in Lead Zirconate Titanate
• Damped Soft Phonons and Diffuse Scattering in 40PMN-60PT
• Neutron and X-ray diffraction study of cubic [111] field cooled Pb(Mg1/3Nb2/3)O3

Cited by in corpus (6)

• Coexistence of local structural heterogeneities and long-range ferroelectricity in Pb-free (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 ceramics
• A new inelastic neutron spectrometer HODACA
• Fluctuating defects in the incipient relaxor K${}_{1-x}$Li${}_x$TaO${}_3$ (x=0.02)
• Simulating the radiofrequency dielectric response of relaxor ferroelectrics: Combination of Coarse-Grained Hamiltonians and Kinetic Monte Carlo
• Coincident onset of charge order and pseudogap in a homogeneous high-temperature superconductor
• Resonance Damping of the THz-frequency Transverse Acoustic Phonon in the Relaxor Ferroelectric KTa1-xNbxO3