Abstract
Weberite-type oxides are a family of oxides with A3BO7 stoichiometry that can adopt different space groups depending on chemical composition. There is a discrepancy in previous studies as to whether Y3TaO7 is the orthorhombic C2221 or the Ccmm space group. Here, we describe the short- and long-range structural properties of weberite-type Y3TaO7 using neutron total scattering data, which has a high sensitivity to the oxygen sublattice. Simultaneous analysis of both short- and long-range structural data via conventional Rietveld and small box modeling demonstrates that Y3TaO7 is best modeled as C2221. While the Ccmm describes equally well the long-range structure, pair distribution function analysis revealed that the local atomic configuration can be best modelled as C2221. This is corroborated by first-principles calculations that confirm the energetic preference of the C2221 over Ccmm. Neutron total scattering data are reported for the first time for the Y3TaO7 weberite-type ceramics.
Original language | English |
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Pages (from-to) | 704-709 |
Number of pages | 6 |
Journal | Acta Materialia |
Volume | 196 |
DOIs | |
State | Published - Sep 1 2020 |
Externally published | Yes |
Funding
This work was supported by the U.S. Department of Energy , Office of Science, Basic Energy Sciences, under Award DE-SC0020321. E.C.O. acknowledges support from the U.S. Department of Energy , Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DESC0014664. The research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. We thank Michelle Everett (ORNL) for guidance during the neutron scattering experiments. ✰ This work was supported by the U.S. Department of Energy , Office of Science, Basic Energy Sciences, under Award DE-SC0020321 ?This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award DE-SC0020321This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award DE-SC0020321. E.C.O. acknowledges support from the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under contract number DESC0014664. The research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. We thank Michelle Everett (ORNL) for guidance during the neutron scattering experiments.
Keywords
- Crystalline oxides
- Density functional theory
- Neutron diffraction
- Pair distribution function analysis
- Rare-earth