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

Abstract

Acoustic properties of Pb͓͑Zn 1/3 Nb 2/3 ͒ 0.91 Ti 0.09 ͔O 3 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 T B ϳ 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 T B , 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.

Central peak and acoustic anomalies of the relaxor ferroelectric lead magnesium niobate-lead titanate single crystal studied by the micro-Brillouin scattering

“…22͒ and recent light scattering studies on PZN-9%PT crystal. 16 It is about 100 K below this temperature where the quasielastic CP becomes more prominent as observed in PLZT relaxor 23 and in the present case also. A similar trend of the CP has also been reported for PMN-32%PT crystal by neutron scattering experiments 24 and associated with the dynamical evolution of PMRs.…”

“…15 Recent light scattering studies on PZN-xPT crystal have indicated the existence of an intermediate temperature at which the coupling between the PMRs and acoustic modes becomes more visible. 16 In this letter we present a direct evidence of mode coupling that gives rise to line shape anomalies in the light scattering spectra of the PMN-33%PT ͓001͔-oriented single crystal using the high-resolution micro-Brillouin scattering.…”

Brillouin scattering studies of acoustic phonon modes and central peak in single-crystal Pb(Sc1/2Ta1/2)OSivasubramanian1, Kojima2 2012Phys. Rev. B

“…In relaxor ferroelectrics, CP that begins to appear well above T m is attributed to the relaxational dynamics of PNRs. 5,7 As shown in Fig. 7, the decrease in the width and increase in the integrated intensity of CP indicates critical slowing down of the relaxation time and increase in the correlations between the PNRs with decrease in temperature.…”

“…2 Extensive studies on the dynamical aspects of PNRs have been carried out in prototype RFEs such as Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) and other related systems through neutron and light scattering studies. [3][4][5][6][7][8][9] Brillouin scattering studies in these systems directly revealed the dynamical features of the PNRs such as the slowing down of their relaxation time and the coupling between the polarization fluctuations and acoustic phonon modes through the appearance of central peak (CP) and softening of the acoustic phonon mode. [6][7][8][9] This paper focuses on micro-Brillouin scattering studies on the dynamical aspects of PNRs in partially ordered Pb(Sc 1/2 Ta 1/2 )O 3 (PST) without any Pb vacancies.…”

Ferroelectric precursor behavior of highly cation-ordered PbSc0.5Ta0.5O3 detected by acoustic emission: Tweed and polar nanoregions

“…12-21,30-35 On further cooling, a smeared frequency dependent temperature maximum of the dielectric response occurs near T m and, slightly below T m the freezing occurs at the freezing temperature T f , similar to polar-glass phases. [36][37][38][39] In contrast to these observations, one finds that AE studies [12][13][14][15][16][17][18][19]22,23,[25][26][27][28][29][30] show extremely sharp singularities at T d and T * , which is sometimes related to changes of the thermal expansion. 40 While this behavior is unlikely when the anomaly is close to the Widom line and far away from the transition point, 41 we will also show in this paper that AE persists even without any changes in thermal expansion.…”