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Title: Atomic-level structural correlations across the morphotropic phase boundary of a ferroelectric solid solution: xBiMg 1/2Ti 1/2O 3-(1$-$x)PbTiO 3

Abstract

Revelation of unequivocal structural information at the atomic level for complex systems is uniquely important for deeper and generic understanding of the structure property connections and a key challenge in materials science. Here in this paper we report an experimental study of the local structure by applying total elastic scattering and Raman scattering analyses to an important non-relaxor ferroelectric solid solution exhibiting the so-called composition-induced morphotropic phase boundary (MPB), where concomitant enhancement of physical properties have been detected. The powerful combination of static and dynamic structural probes enabled us to derive direct correspondence between the atomic-level structural correlations and reported properties. The atomic pair distribution functions obtained from the neutron total scattering experiments were analysed through big-box atom-modelling implementing reverse Monte Carlo method, from which distributions of magnitudes and directions of off-centred cationic displacements were extracted. We found that an enhanced randomness of the displacement-directions for all ferroelectrically active cations combined with a strong dynamical coupling between the A- and B-site cations of the perovskite structure, can explain the abrupt amplification of piezoelectric response of the system near MPB. Finally, altogether this provides a more fundamental basis in inferring structure-property connections in similar systems including important implications in designing novelmore » and bespoke materials.« less

Authors:
 [1];  [2];  [3]; ORCiD logo [4];  [1]
  1. Univ. of Hamburg (Germany). Dept. of Earth Sciences
  2. Univ. of Erlangen-Nuremberg, Erlangen (Germany). Dept. of Crystallography and Structure Physics
  3. Univ. of Science and Technology, Beijing (China). School of Metallurgical and Ecological Engineering
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1349603
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Datta, Kaustuv, Neder, Reinhard B., Chen, Jun, Neuefeind, Joerg C., and Mihailova, Boriana. Atomic-level structural correlations across the morphotropic phase boundary of a ferroelectric solid solution: xBiMg1/2Ti1/2O3-(1$-$x)PbTiO3. United States: N. p., 2017. Web. doi:10.1038/s41598-017-00530-z.
Datta, Kaustuv, Neder, Reinhard B., Chen, Jun, Neuefeind, Joerg C., & Mihailova, Boriana. Atomic-level structural correlations across the morphotropic phase boundary of a ferroelectric solid solution: xBiMg1/2Ti1/2O3-(1$-$x)PbTiO3. United States. doi:10.1038/s41598-017-00530-z.
Datta, Kaustuv, Neder, Reinhard B., Chen, Jun, Neuefeind, Joerg C., and Mihailova, Boriana. Tue . "Atomic-level structural correlations across the morphotropic phase boundary of a ferroelectric solid solution: xBiMg1/2Ti1/2O3-(1$-$x)PbTiO3". United States. doi:10.1038/s41598-017-00530-z. https://www.osti.gov/servlets/purl/1349603.
@article{osti_1349603,
title = {Atomic-level structural correlations across the morphotropic phase boundary of a ferroelectric solid solution: xBiMg1/2Ti1/2O3-(1$-$x)PbTiO3},
author = {Datta, Kaustuv and Neder, Reinhard B. and Chen, Jun and Neuefeind, Joerg C. and Mihailova, Boriana},
abstractNote = {Revelation of unequivocal structural information at the atomic level for complex systems is uniquely important for deeper and generic understanding of the structure property connections and a key challenge in materials science. Here in this paper we report an experimental study of the local structure by applying total elastic scattering and Raman scattering analyses to an important non-relaxor ferroelectric solid solution exhibiting the so-called composition-induced morphotropic phase boundary (MPB), where concomitant enhancement of physical properties have been detected. The powerful combination of static and dynamic structural probes enabled us to derive direct correspondence between the atomic-level structural correlations and reported properties. The atomic pair distribution functions obtained from the neutron total scattering experiments were analysed through big-box atom-modelling implementing reverse Monte Carlo method, from which distributions of magnitudes and directions of off-centred cationic displacements were extracted. We found that an enhanced randomness of the displacement-directions for all ferroelectrically active cations combined with a strong dynamical coupling between the A- and B-site cations of the perovskite structure, can explain the abrupt amplification of piezoelectric response of the system near MPB. Finally, altogether this provides a more fundamental basis in inferring structure-property connections in similar systems including important implications in designing novel and bespoke materials.},
doi = {10.1038/s41598-017-00530-z},
journal = {Scientific Reports},
number = 1,
volume = 7,
place = {United States},
year = {Tue Mar 28 00:00:00 EDT 2017},
month = {Tue Mar 28 00:00:00 EDT 2017}
}

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Cited by: 2works
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  • The solid solution between the normal ferroelectric Pb(Zr{sub 1/2}Ti{sub 1/2})O{sub 3} (PZT) and relaxor ferroelectric Pb(Ni{sub 1/3}Nb{sub 2/3})O{sub 3} (PNN) was synthesized by the columbite method. The phase structure and dielectric properties of xPZT-(1-x)PNN where x=0.4-0.9 and the Zr/Ti composition was fixed close to the morphotropic phase boundary (MPB) were investigated. With these data, the ferroelectric phase diagram between PZT and PNN has been established. The relaxor ferroelectric nature of PNN gradually transformed towards a normal ferroelectric state towards the composition 0.7PZT-0.3PNN, in which the permittivity was characterized by a sharp peak and the disappearance of dispersive behavior. X-ray diffractionmore » analysis demonstrated the coexistence of both the rhombohedral and tetragonal phases at the composition 0.8PZT-0.2PNN, a new morphotropic phase boundary within this system. Examination of the dielectric spectra indicates that PZT-PNN exhibits an extremely high relative permittivity near the MPB composition. The permittivity shows a shoulder at the rhombohedral to tetragonal phase transition temperature T{sub RT}=195 deg. C, and then a maximum permittivity (36 000 at 10 kHz) at the transition temperature T{sub max}=277 deg. C at the MPB composition. The maximum transition temperature of this system was 326 deg. C at the composition x=0.9 with the relative permittivity of 32 000 at 10 kHz.« less
  • We present here the results of structural studies on multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution using Rietveld analysis on powder x-ray diffraction data in the composition range 0.35 ≤ x ≤ 0.55. The stability region of various crystallographic phases at room temperature for (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} is determined precisely. Structural transformation from pseudo-cubic (x ≤ 0.40) to tetragonal (x ≥ 0.50) phase is observed via phase coexistence region demarcating the morphotropic phase boundary. The morphotropic phase boundary region consists of coexisting tetragonal and monoclinic structures with space group P4mm and Pm, respectively, stable in composition range 0.41 ≤ x ≤ 0.49 as confirmed by Rietveld analysis. The resultsmore » of Rietveld analysis completely rule out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier workers. A comparison between the bond lengths for “B-site cations-oxygen anions” obtained after Rietveld refinement, with the bond length calculated using Shannon-Prewitt ionic radii, reveals the ionic nature of B-O (Ni/Ti-O) bonds for the cubic phase and partial covalent character for the other crystallographic phases.« less
  • X-ray and neutron diffraction techniques are combined with first-principles-based simulations to derive and understand the structural properties of Pb(Sc,Nb,Ti)O{sub 3} (PSN-PT) near its morphotropic phase boundary (MPB). An analysis of our measurements yields, at room and low temperatures, an overall tetragonal T--monoclinic M{sub C}--monoclinic M{sub B}--rhombohedral R path (when adopting the notations of Vanderbilt and Cohen, Phys. Rev. B 63, 94108 (2001) for the monoclinic phases) as the Ti composition decreases across the MPB. A composition- and temperature-dependent significant mixing between some of these phases is also measured and reported here. The overall T-M{sub C}-M{sub B}-R path, which has alsomore » been proposed for Pb(Mg,Nb,Ti)O{sub 3} [A. K. Singh and D. Pandey, Phys. Rev. B 67, 64102 (2003)] is rather complex since it involves a change in the polarization path: this polarization first rotates in a (100) plane for the T-M{sub C} part of the path and then in a (1-10) plane for the M{sub B}-R part of the path. Moreover, a comparison between these measurements and first-principles-based calculations raises the possibility that this complex path, and the associated M{sub C} and M{sub B} phases, can only occur if the samples exhibit a deviation from a perfectly homogeneous and disordered situation, e.g. possess nanoscale chemically-ordered regions. If not, homogeneously disordered PSN-PT is predicted to exhibit at low temperature the same polarization path as Pb(Zr,Ti)O{sub 3}, that is T-monoclinic M{sub A}-R which involves a 'single' polarization rotation in a (1-10) plane. Nanoscale inhomogeneity may thus play a key role on the macroscopic properties of PSN-PT, in particular, and of other heterovalent complex solid solutions, in general, near their MPB.« less
  • X-ray absorption fine structure (XAFS) experiments were carried out on a series of ferroelectric materials PbZr{sub 1-x}Ti{sub x}O{sub 3} (PZT) (x=0.40,0.47,0.49,0.55) to study the local structure around Ti and Zr atoms in each sample. Based on the fact that PZT has a single phase in the morphotropic phase boundary (MPB) from the x-ray diffraction measurements, both extended XAFS (EXAFS) and x-ray absorption near-edge structure results suggest that at 3 K the orientation of the Ti off-center displacement in these materials changes gradually from the [001] to [111] direction (in pseudocubic notation) as the Ti concentration x decreases from 0.55 tomore » 0.40. This is evidence for a continuous rotation of the local electrical polarization across the MPB region in PZT. The Zr K-edge EXAFS data suggest that at low temperature, the ZrO{sub 6} octahedra in PZT are less distorted than indicated from the average structure for all samples, though a small Zr displacement relative to the O atoms may exist. This possible small Zr displacement is also much less than that found in density functional theory calculations. The ZrO{sub 6} local structure hardly changes with Ti concentration across the MPB region. Finally, the XAFS data also show that the sizes of the ZrO{sub 6} octahedra are larger than that of the TiO{sub 6} octahedra which was also observed by experimental neutron pair distribution function analysis.« less
  • In this paper, two displacive phase transitions around the morphotropic phase boundary (MPB) in Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}-x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) ceramics were detected by inspecting two anomalies of the Raman Ti{sup 4+}-O{sup 2−} longitudinal optical mode (∼725 cm{sup −1}). Further, permittivity and X-ray diffraction results demonstrated these two phase transitions originate from tetragonal (T) to rhombohedral (R) through an intermediate orthorhombic (O) phase. Importantly, we found that the maximum piezoelectric response (d{sub 33} = 545pC/N) was achieved at the boundary between the T and O phase, indicating that the giant piezoelectricity of BZT-xBCT may mainly stem from the T-O phase boundarymore » due to easier polarization rotation and larger lattice softening.« less