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Title: Damped Soft Phonons and Diffuse Scattering in 40% Pb(Mg1/3Nb2/3))3-60% PbTiO3

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914165
Report Number(s):
BNL-78733-2007-JA
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. B; Journal Volume: 73
Country of Publication:
United States
Language:
English
Subject:
national synchrotron light source

Citation Formats

Stock,C., Ellis, D., Swainson, I., Xu, G., Hiraka, H., Zhong, Z., Luo, H., Zhao, X., Viehland, D., and et al. Damped Soft Phonons and Diffuse Scattering in 40% Pb(Mg1/3Nb2/3))3-60% PbTiO3. United States: N. p., 2006. Web. doi:10.1103/PhysRevB.73.064107.
Stock,C., Ellis, D., Swainson, I., Xu, G., Hiraka, H., Zhong, Z., Luo, H., Zhao, X., Viehland, D., & et al. Damped Soft Phonons and Diffuse Scattering in 40% Pb(Mg1/3Nb2/3))3-60% PbTiO3. United States. doi:10.1103/PhysRevB.73.064107.
Stock,C., Ellis, D., Swainson, I., Xu, G., Hiraka, H., Zhong, Z., Luo, H., Zhao, X., Viehland, D., and et al. Sun . "Damped Soft Phonons and Diffuse Scattering in 40% Pb(Mg1/3Nb2/3))3-60% PbTiO3". United States. doi:10.1103/PhysRevB.73.064107.
@article{osti_914165,
title = {Damped Soft Phonons and Diffuse Scattering in 40% Pb(Mg1/3Nb2/3))3-60% PbTiO3},
author = {Stock,C. and Ellis, D. and Swainson, I. and Xu, G. and Hiraka, H. and Zhong, Z. and Luo, H. and Zhao, X. and Viehland, D. and et al.},
abstractNote = {},
doi = {10.1103/PhysRevB.73.064107},
journal = {Phys. Rev. B},
number = ,
volume = 73,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • Using neutron elastic and inelastic scattering and high-energy x-ray diffraction, we present a comparison of 40% Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60% PbTiO{sub 3} (PMN-60PT) with pure Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} (PMN) and PbTiO{sub 3} (PT). We measure the structural properties of PMN-60PT to be identical to pure PT, however, the lattice dynamics are exactly that previously found in relaxors PMN and Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3} (PZN). PMN-60PT displays a well-defined macroscopic structural transition from a cubic to tetragonal unit cell at 550 K. The diffuse scattering is shown to be weak indicating that the structural distortion is long-range in PMN-60PT andmore » short-range polar correlations (polar nanoregions) are not present. Even though polar nanoregions are absent, the soft optic mode is short-lived for wave vectors near the zone center. Therefore PMN-60PT displays the same waterfall effect as prototypical relaxors PMN and PZN. We conclude that it is random fields resulting from the intrinsic chemical disorder which is the reason for the broad transverse optic mode observed in PMN and PMN-60PT near the zone center and not due to the formation of short-ranged polar correlations. Through our comparison of PMN, PMN-60PT, and pure PT, we interpret the dynamic and static properties of the PMN-xPT system in terms of a random field model in which the cubic anisotropy term dominates with increasing doping of PbTiO{sub 3}.« less
  • Pb(Zr,Ti)O3 (PZT) based compositions have been challenging to texture or grow in a single crystal form due to the incongruent melting point of ZrO2. Here we demonstrate the method for achieving 90% textured PZT-based ceramics and further show that it can provide highest known energy density in piezoelectric materials through enhancement of piezoelectric charge and voltage coefficients (d and g). Our method provides more than 5 increase in the ratio d(textured)/d(random). A giant magnitude of d g coefficient with value of 59 000 10 15 m2 N 1 (comparable to that of the single crystal counterpart and 359% higher thanmore » that of the best commercial compositions) was obtained.« less
  • No abstract prepared.
  • We report the results of neutron elastic scattering measurements between -250oC and 620oC on the lead-free relaxor Na1/2Bi1/2TiO3 (NBT). Strong, anisotropic, elastic diffuse scattering intensity decorates the (100), (110), (111), (200), (220), and (210) Bragg peaks at room temperature. The wavevector dependence of this diffuse scattering is compared to that in the lead-based relaxor PbMg1/3Nb2/3O3 (PMN) to determine if any features might be common to relaxors. Prominent ridges in the elastic diffuse scattering intensity contours that extend along <110> are seen that exhibit the same zone dependence as those observed in PMN and other lead-based relaxors. These ridges disappear graduallymore » on heating above the cubic-to-tetragonal phase transition temperature TCT = 523oC, which is also near the temperature at which the dielectric permittivity begins to deviate from Curie-Weiss behavior. We thus identify the <110>-oriented ridges as a relaxor-specific property. The diffuse scattering contours also display narrower ridges oriented along <100> that are consistent with the x-ray results of Kreisel et al. (2003); these vanish below 320oC indicating that they have a different physical origin. The <100>-oriented ridges are not observed in PMN. We observe no equivalent relaxor-specific elastic diffuse scattering from the homovalent relaxor analogues K0.95Li0.05TiO3 (A-site disordered) and KTa0.95Nb0.05O3 (B-site disordered). This suggests that the <110>-oriented diffuse scattering ridges are correlated with the presence of strong random electric fields and invites a reassessment of what defines the relaxor phase. We find that doping NBT with 5.6% BaTiO3, a composition close to the morphotropic phase boundary with enhanced piezoelectric properties, increases the room temperature correlation length along [1 1 0] from 40 to 60 while doubling the associated integrated diffuse scattering. Similar behavior was reported by Matsuura et al. (2006) for compositions of PMN doped with PbTiO3. Finally, we comment on the recent observation of monoclinicity in NBT at room temperature by placing a strict bound on the strength of the ( ) superlattice reflection associated with the Cc space group based on the atomic coordinates published in the x-ray study by Aksel et al. (2011) for NBT. We argue that a skin effect, analogous to that reported in the relaxors PZN and PMN-10%PT, can reconcile our single-crystal data with the powder data of Aksel et al. We believe this represents the first evidence of the relaxor skin effect in a lead-free relaxor.« less