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Title: Local and average structures of BaTiO3-Bi(Zn1/2Ti1/2)O3

The complex crystallographic structures of (1-x)BaTiO3-xBi(Zn1/2Ti1/2)O3 (BT-xBZT) are examined using high resolution synchrotron X-ray diffraction, neutron diffraction, and neutron pair distribution function (PDF) analyses. The short-range structures are characterized from the PDFs, and a combined analysis of the X-ray and neutron diffraction patterns is used to determine the long-range structures. Our results demonstrate that the structure appears different when averaged over different length scales. In all compositions, the local structures determined from the PDFs show local tetragonal distortions (i.e., c/a > 1). But, a box-car fitting analysis of the PDFs reveals variations at different length scales. For 0.80BT-0.20BZT and 0.90BT-0.10BZT, the tetragonal distortions decrease at longer atom-atom distances (e.g., 30 vs. 5 ). When the longest distances are evaluated (r > 40 ), the lattice parameters approach cubic. Neutron and X-ray diffraction yield further information about the long-range structure. Compositions 0.80BT-0.20BZT and 0.90BT-0.10BZT appear cubic by Bragg diffraction (no peak splitting), consistent with the PDFs at long distances. However, these patterns cannot be adequately fit using a cubic lattice model; modeling their structures with the P4mm space group allows for a better fit to the patterns because the space group allows for c-axis atomic displacements that occur at the localmore » scale. Furthermore, for the compositions 0.92BT-0.08BZT and 0.94BT-0.06BZT, strong tetragonal distortions are observed at the local scale and a less-distorted tetragonal structure is observed at longer length scales. In Rietveld refinements, the latter is modeled using a tetragonal phase. Since the peak overlap in these two-phase compositions limits the ability to model the local-scale structures as tetragonal, it is approximated in the refinements as a cubic phase. These results demonstrate that alloying BT with BZT results in increased disorder and disrupts the long-range ferroelectric symmetry present in BT, while the large tetragonal distortion present in BZT persists at the local scale.« less
Authors:
ORCiD logo [1] ;  [2] ; ORCiD logo [3] ;  [4] ;  [5] ;  [6] ;  [3]
  1. North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division
  2. North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; King Mongkut's Univ. of Technology North Bangkok (Thailand). Dept. of Industrial Physics adn Medical Instrumentation
  3. North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering
  4. Oregon State Univ., Corvallis, OR (United States). School of Mechanical, Industrial, and Manufacturing Engineering; Chulalongkorn Univ., Bangkok (Thailand). Dept. of Materials Science
  5. Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331, USA; Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakornpathom 73000, Thailand
  6. Oregon State Univ., Corvallis, OR (United States). School of Mechanical, Industrial, and Manufacturing Engineering
Publication Date:
Grant/Contract Number:
AC05-00OR22725; AC52-06NA25396; AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 120; Journal Issue: 18; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; dielectrics; local structure; diffraction; BaTiO3
OSTI Identifier:
1337028
Alternate Identifier(s):
OSTI ID: 1331826