Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg1/3Ta2/3O3

Lushnikov, S. G.; Fedoseev, A. I.; Gvasaliya, S. N.; Ko, Jae‐Hyeon; Kojima, Seiji

doi:10.1088/0953-8984/19/49/496206

Cited by 7 publications

(9 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The FWHM of the LA mode of PMN and PMT begins to increase at approximately 350 and 400 K, respectively, which are much lower than their T B 's. 42,44 Similar results have also been observed in other RFEs such as PMN-xPT single crystals with x = 33% -35%. 50,51 Recent acoustic emission measurements on PZN-xPT with x = 4.5% -12% showed that strong acoustic activity was observed at almost the same temperature of about 500 K irrespective of the PT content, and this result was attributed to local microscopic phase transition in PNRs embedded in a nonpolar cubic matrix based on the fact that the acoustic emission signal is normally very sensitive to small structural changes.…”

Section: Discussionsupporting

confidence: 71%

“…It was also found that the acoustic damping of the LA waves of PMT begins to increase below this temperature upon cooling. 44 These behaviors are very similar to those observed from PZN-4.5%PT and PZN-9%PT single crystals. Therefore, we may suggest that the electrostrictive coupling constant between the LA waves and PNRs is different from that between the TA waves and PNRs.…”

Section: B Longitudinal and Transverse Acoustic Modes Of Pzn-xptsupporting

confidence: 81%

See 1 more Smart Citation

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

Kim

Kojima

2008

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Temperature dependence of acoustic behaviors and quasielastic central peaks ͑CPs͒ of Pb͓͑Zn 1/3 Nb 2/3 ͒ x Ti 1−x ͔O 3 ͑PZN-xPT͒ single crystals with x = 4.5% and 9% have been investigated in a temperature range of 300-900 K by using the Brillouin light scattering. The temperature dependence of the C 11 elastic constant of both crystals showed a deviation from normal lattice anharmonicity at the Burns temperature ͑T B ͒ of about 730 K upon cooling, indicating the onset of the electrostrictive coupling between the polar nanoregions ͑PNRs͒ and the longitudinal acoustic ͑LA͒ waves. Upon further cooling, depolarized CP began to appear at a certain temperature ͑T d ͒ located in 500-550 K, which was accompanied by substantial softening of the C 44 elastic constant below this temperature suggesting anisotropic electrostrictive coupling between PNRs and the two acoustic waves. In addition, the onset of significant increase in the acoustic damping of both acoustic waves at T d could be seen from the temperature dependence of the linewidth of Brillouin doublets. These results suggested that electrostrictive coupling of the strain to the square of the local polarization of PNRs and the resultant order-parameter fluctuations are enhanced not at T B but at a much lower temperature of T d , which may be ascribed to a local structural transformation occurring in PNRs at T d. This suggestion is consistent with recent studies on PZN-xPT single crystals reporting the appearance of strong acoustic emission signals ͓M. Roth et al., Phys. Rev. Lett. 98, 265701 ͑2007͔͒ and substantial changes in the Raman spectrum ͓O. Svitelskiy, Phys. Rev. B 72, 172106 ͑2005͔͒ at almost the same temperature. From the comparison of the present results to those of two typical relaxors, Pb͑Mg 1/3 Nb 2/3 ͒O 3 and Pb͑Mg 1/3 Ta 2/3 ͒O 3 , it was suggested that the existence of an intermediate characteristic temperature T d below T B may be considered as a more common characteristic in the temperature evolution of PNRs of relaxor ferroelectrics.

show abstract

Section: Discussionsupporting

confidence: 71%

Section: B Longitudinal and Transverse Acoustic Modes Of Pzn-xptsupporting

confidence: 81%

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

Kim

Kojima

2008

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the prototype RFEs such as PMN and PMT indeed the elastic constant begins to exhibit a gradual decrease below T B . 20,21 In these systems, the decrease in the elastic constant from T B evolves continuously with a broad minimum at T m . For PST also, as in prototype relaxors, quadratic coupling between the PNRs and strain is clearly manifested with the gradual decrease in the frequency of the LA phonon at T B = 600 K followed by increase in its width notably from 450 K as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Brillouin scattering studies of acoustic phonon modes and central peak in single-crystal Pb(Sc1/2Ta1/2)O
Sivasubramanian
¹
,
Kojima
²

2012
Phys. Rev. B

View full text Add to dashboard Cite

Brillouin spectra measurements have been carried out from 800 to 100 K for Pb(Sc 1/2 Ta 1/2 )O 3 in back-scattering geometry. The frequency of the longitudinal acoustic (LA) phonon begins to show marked softening followed by an increase in its width below the intermediate temperature T * = 450 K. The gradual increase in the width of the LA phonon below T * is attributed to the electrostrictive coupling between the local polarization and strain. The frequency of the LA phonon mode exhibits anomalous behavior around 295 K, the phase transition temperature. The width of the LA phonon exhibits a sharp Landau-Khalatnikov-like maximum at 295 K. A central peak begins to appear around T * and exhibits critical slowing down upon further cooling. The relaxation times calculated for the LA phonon and central peak indicate the order-disorder nature of the phase transition.

show abstract

“…Since the macroscopic structure of PMT is cubic, the selection rule permits only the excitation of LA phonon mode in the backscattering geometry. The corresponding elastic constant C 11 is given by the following expressions [ 60 ]:

where ν LA , Γ , V 11 and α in Equation (5) are the frequency, width, velocity and attenuation of the LA phonon, and ρ and n are the density and the refractive index of PMT and λ o is the wavelength of the incident photon. Using the parameters of the LA phonon, C 11 and α were calculated using the known values of ρ = 9.65 gm/cm 3 and the refractive index n = 2.475 for PMT [ 60 ].…”

Section: Resultsmentioning

confidence: 99%

“…The corresponding elastic constant C 11 is given by the following expressions [ 60 ]:

Section: Resultsmentioning

confidence: 99%

Anomalies of Brillouin Light Scattering in Selected Perovskite Relaxor Ferroelectric Crystals

2023

Self Cite

View full text Add to dashboard Cite

Compositionally disordered perovskite compounds have been one of the exotic topics of research during the past several years. Colossal piezoelectric and electrostrictive effects have been observed in disordered perovskite ferroelectric materials. The key ingredient in the physical behavior of disordered perovskites is the nucleation and growth of the local dipolar regions called polar nanoregions (PNRs). PNRs begin to nucleate far above the temperature of the dielectric maximum Tm and exhibit varied relaxation behavior with temperature. The evidence for the existence of various stages in the relaxation dynamics of PNRs was revealed through the study of the temperature evolution of optical phonons by Raman scattering. The quasi-static regime of PNRs is characterized by the strong coupling between the local polarization and strain with the local structural phase transition and the critical slowing of the relaxation time. Strong anomalies in the frequency and the width of the acoustic phonons, and emergence of the central peak in the quasi-static region of the relaxation dynamics of PNRs have been observed through Brillouin scattering studies. In this review, we discuss the anomalies observed in Brillouin scattering in selected disordered perovskite ferroelectrics crystals such as Pb(Mg1/3Ta2/3)O3, Pb(Sc1/2Ta1/2)O3, 0.65PIN-0.35PT and Sr0.97Ca0.03TiO3 to understand dynamical behavior of PNRs.

show abstract

Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg_1/3Ta_2/3O₃

Cited by 7 publications

References 28 publications

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

Brillouin scattering studies of acoustic phonon modes and central peak in single-crystal Pb(Sc1/2Ta1/2)O
Sivasubramanian
¹
,
Kojima
²

2012
Phys. Rev. B

Anomalies of Brillouin Light Scattering in Selected Perovskite Relaxor Ferroelectric Crystals

Contact Info

Product

Resources

About

Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg1/3Ta2/3O3

Cited by 7 publications

References 28 publications

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

Central peaks, acoustic modes, and the dynamics of polar nanoregions inPb[(Zn1∕3Nb2∕3

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

Anomalies of Brillouin Light Scattering in Selected Perovskite Relaxor Ferroelectric Crystals

Contact Info

Product

Resources

About

Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg_1/3Ta_2/3O₃

Brillouin scattering studies of acoustic phonon modes and central peak in single-crystal Pb(Sc1/2Ta1/2)O
Sivasubramanian
¹
,
Kojima
²

2012
Phys. Rev. B