Mode-coupling and polar nanoregions in the relaxor ferroelectric Pb(Mg1/3Nb2/3)O3

Abstract

We present a quantitative analysis of the phonon lineshapes obtained by neutron inelastic scattering methods in the relaxor ferroelectric Pb(Mg1/3Nb2/3)O3 (PMN). Differences in the shapes and apparent positions of the transverse acoustic (TA) and transverse optic (TO) phonon peaks measured in the (300) and (200) Brillouin zones at 690 K are well described by a simple model that couples the TA and soft TO modes in which the primary parameter is the wave vector and temperature-dependent TO linewidth Gamma(q,T). This mode-coupling picture provides a natural explanation for the uniform displacements of the polar nanoregions, discovered by Hirota et al., as the PNR result from the condensation of a soft TO mode that also contains a large acoustic component.

arXiv comment9 pages, 8 figures

References in corpus (5)

• Neutron Diffuse Scattering from Polar Nanoregions in the Relaxor Pb(Mg1/3Nb2/3)O3
• Soft Mode Dynamics Above and Below the Burns Temperature in the Relaxor Pb(Mg_1/3Nb_2/3)O_3
• Ferroelectric Ordering in the Relaxor Pb(Mg1/3Nb2/3)O3 as Evidenced by Low-Temperature Phonon Anomalies
• Soft Phonon Anomalies in the Relaxor Ferroelectric Pb(Zn_1/3Nb_2/3)_0.92Ti_0.08O_3
• Dynamical effects of the nanometer-sized polarized domains in Pb(Zn1/3Nb2/3)O3

Cited by in corpus (21)

• Phase instability induced by polar nanoregions in a relaxor ferroelectric system
• A Neutron Elastic Diffuse Scattering Study of PMN
• A reassessment of the Burns temperature and its relationship to the diffuse scattering, lattice dynamics, and thermal expansion in the relaxor PMN
• Origin of the "Waterfall" Effect in Phonon Dispersion of Relaxor Perovskites
• Central mode and soft mode behavior in PbMg1/Nb2/3O3 relaxor ferroelectric
• Universal Static and Dynamic Properties of the Structural Transition in Pb(Zn1/3Nb2/3)O3
• Cold neutron scattering study on diffuse and phonon excitations in the relaxor PbMg(1/3)Nb(2/3)O3
• A Universal Phase Diagram for PMN-xPT and PZN-xPT
• Quasi-Elastic Scattering, Random Fields and phonon-coupling effects in PbMg1/3Nb2/3O3
• Strong Influence of the diffuse component on the lattice dynamics in Pb(Mg${}_{1/3}$Nb${}_{2/3}$)O${}_3$
• Disorder and relaxation mode in the lattice dynamics of PbMg${}_{1/3}$Nb${}_{2/3}$O${}_3$ relaxor ferroelectric
• Dielectric relaxation and polar phonon softening in relaxor ferroelectric PbMg_(1/3)Ta_(2/3)O_3
• Far-infrared soft mode behavior in PST thin films
• Polar and non-polar atomic motions in the relaxor ferroelectric PLZT from dielectric, anelastic and NMR relaxation
• Dynamic origin of the morphotropic phase boundary - Soft modes and phase instability in 0.68Pb(Mg1/3Nb2/3O3)-0.32PbTiO3
• Evidence for anisotropic polar nanoregions in relaxor PMN: A neutron study of the elastic constants and anomalous TA phonon damping
• Quantum paraelectric behavior of pyrochlore PMN
• The Structural Phase Transition of the Relaxor Ferroelectric 68%PbMg1/3Nb2/3O3-32%PbTiO3
• Localized microwave resonances in strained SrTiO3 thin films
• Spontaneous decay of a soft optical phonon in the relaxor ferroelectric PbMg${}_{1/3}$Nb${}_{2/3}$O${}_3$
• Transverse acoustic phonon anomalies at intermediate wavevectors in MgV${}_2$O${}_4$