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Title: Damped soft phonons and diffuse scattering in 40%Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60%PbTiO{sub 3}

Abstract

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 and 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 themore » 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

Authors:
 [1];  [2];  [1];  [3]; ; ;  [4];  [5]; ;  [6];  [7];  [1];  [2]
  1. Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)
  2. (United States)
  3. National Research Council, Chalk River, Ontario KOJ 1JO (Canada)
  4. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)
  5. National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)
  6. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China)
  7. Department of Materials Science and Engineering, Virginia Tech., Blacksburg, Virginia 24061 (United States)
Publication Date:
OSTI Identifier:
20787894
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 73; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevB.73.064107; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; COMPARATIVE EVALUATIONS; CORRELATIONS; DIFFUSE SCATTERING; FERROELECTRIC MATERIALS; INELASTIC SCATTERING; LEAD COMPOUNDS; NEUTRON DIFFRACTION; PHASE TRANSFORMATIONS; PHONONS; RANDOMNESS; SOLIDS; TITANATES; VECTORS; X-RAY DIFFRACTION

Citation Formats

Stock, C., Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, Ellis, D., Swainson, I. P., Xu, Guangyong, Hiraka, H., Shirane, G., Zhong, Z., Luo, H., Zhao, X., Viehland, D., Birgeneau, R. J., and Department of Physics, University of California at Berkeley, Berkeley, California 94720. Damped soft phonons and diffuse scattering in 40%Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60%PbTiO{sub 3}. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.0.
Stock, C., Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, Ellis, D., Swainson, I. P., Xu, Guangyong, Hiraka, H., Shirane, G., Zhong, Z., Luo, H., Zhao, X., Viehland, D., Birgeneau, R. J., & Department of Physics, University of California at Berkeley, Berkeley, California 94720. Damped soft phonons and diffuse scattering in 40%Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60%PbTiO{sub 3}. United States. doi:10.1103/PHYSREVB.73.0.
Stock, C., Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, Ellis, D., Swainson, I. P., Xu, Guangyong, Hiraka, H., Shirane, G., Zhong, Z., Luo, H., Zhao, X., Viehland, D., Birgeneau, R. J., and Department of Physics, University of California at Berkeley, Berkeley, California 94720. Wed . "Damped soft phonons and diffuse scattering in 40%Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60%PbTiO{sub 3}". United States. doi:10.1103/PHYSREVB.73.0.
@article{osti_20787894,
title = {Damped soft phonons and diffuse scattering in 40%Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-60%PbTiO{sub 3}},
author = {Stock, C. and Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 and Ellis, D. and Swainson, I. P. and Xu, Guangyong and Hiraka, H. and Shirane, G. and Zhong, Z. and Luo, H. and Zhao, X. and Viehland, D. and Birgeneau, R. J. and Department of Physics, University of California at Berkeley, Berkeley, California 94720},
abstractNote = {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 and 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}.},
doi = {10.1103/PHYSREVB.73.0},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 6,
volume = 73,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2006},
month = {Wed Feb 01 00:00:00 EST 2006}
}
  • For the first time, we have grown ferroelectric single crystals Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3}-Pb(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} (PMN-PT-PFN) from the melt by the simple slow cooling process. The chemical composition of the single crystals PMN-PT-PFN (0.59/0.31/0.10) is near the morphotropic phase boundary (MPB). X-ray diffraction (XRD) was used to study phase structure of the as-grown crystals, energy dispersive X-ray spectrometer (EDS) and electron probe micro-analyzer (EPMA) were employed to confirm the chemical composition and element distribution of the as-grown crystals, respectively. The ferroelectric, dielectric and piezoelectric properties of the as-grown PMN-PT-PFN (0.59/0.31/0.10) single crystal oriented along the (0 0more » 1) axis were measured, which showed that the remnant polarization (P{sub r}), coercive electric fields (E{sub c}), the Curie temperature (T{sub c}) and the piezoelectric coefficient (d{sub 33}) were 50.2 {mu}C/cm{sup 2}, 13.9 kV/cm, 158 deg. C and about 1800 pC/N, respectively. All the results indicated that the PMN-PT-PFN (0.59/0.31/0.10) single crystals are promising for applying to field of high frequency.« less
  • Optical properties and phase transitions of Pb(In{sub 1∕2}Nb{sub 1∕2})O{sub 3}-Pb(Mg{sub 1∕3}Nb{sub 2∕3})O{sub 3}-PbTiO{sub 3} (PIN-PMN-PT) crystals near morphotropic phase boundary (MPB) have been investigated by temperature dependent transmittance and reflectance spectra. Three critical point energies E{sub g} = 3.17–3.18 eV, E{sub a} = 3.41–3.61 eV, and E{sub b} = 4.74–4.81 eV can be assigned to the transitions from oxygen 2p to titanium d, niobium d, and lead 6p states, respectively. They show narrowing trends with increasing temperature, which can be caused by thermal expansion of the lattice and electron-phonon interaction. Deviation from the linear behaviors can be observed from E{sub a} and E{sub b} versus PT concentration, indicating amore » complex multiphase structure near MPB region.« less
  • Various domain structures, including wave-like domains, mixed needle-like and laminar domains, typical embedded 90° and 180° domains, have been observed in unpoled rhombohedral, monoclinic, and tetragonal Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} (PIN-PMN-PT) crystals by polarizing light microscope; while in poled tetragonal crystals, the parallel 180° domains were reversed and only vertical 90° domain walls were observed. For 0.24PIN-0.42PMN-0.34PT crystals with morphotropic phase boundary composition, the domain wall motion was in-situ observed as a function of applied electric field along crystallographic [100] direction. With increasing the electric field from 0 to 12 kV/cm, the rhombohedral (R) domains were foundmore » to change to monoclinic (M) domains and then to tetragonal (T) domains. The electric field-induced phase transition was also confirmed by X-ray diffraction and the temperature-dependent dielectric behavior.« less
  • Perovskite solid solutions of 0.2Pb(Zn{sub 1/3}Ta{sub 2/3})O{sub 3}-0.8Pb[(Mg{sub 1/3}Nb{sub 2/3}),Ti]O{sub 3} were synthesized and characterized. Developed structures and the crystallographic symmetries as well as the lattice parameters were investigated. Weak-field dielectric constant and loss values of the ceramics were measured as functions of composition, temperature, and frequency. The dielectric constant spectra in the paraelectric temperature region were also analyzed in terms of diffuseness in the phase transition modes. The results were compared with other substituents of Pb(Mg{sub 1/3}Ta{sub 2/3})O{sub 3}, Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, as well as Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}.