Oxygen order-disorder phase transition in PrBaCo2O5.48 at high temperature

S. Streule; A. Podlesnyak; E. Pomjakushina; K. Conder; D. Sheptyakov; M. Medarde; J. Mesot

doi:10.1016/j.physb.2006.01.244

Oxygen order-disorder phase transition in PrBaCo₂O_5.48 at high temperature

S. Streule, A. Podlesnyak, E. Pomjakushina, K. Conder, D. Sheptyakov, M. Medarde, J. Mesot

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

We have investigated the PrBaCo₂O_5.48 compound by means of neutron powder diffraction at temperatures 300 K < T < 820 K. We observe a new structural phase transition at T_OD = 776 K, which we associate with an oxygen order-disorder transition: the well-known room temperature ordered crystal structure, in which slabs of CoO₆ octahedra and CoO₅ pyramids interleave (Pmmm symmetry) gets lost at temperatures T > T_OD, resulting in a statistical distribution of octahedra and pyramids in the sample. The new phase can be described by the tetragonal P 4 / mmm space group. The transition is caused by displacement of apical oxygen ions and is an indication that ionic conductivity, which has been observed in 3D cobaltites, may also exist in layered cobaltites.

Original language	English
Pages (from-to)	539-540
Number of pages	2
Journal	Physica B: Physics of Condensed Matter
Volume	378-380
Issue number	SPEC. ISS.
DOIs	https://doi.org/10.1016/j.physb.2006.01.244
State	Published - May 1 2006
Externally published	Yes

Funding

This work was performed at the spallation neutron source SINQ of the Paul Scherrer Institute, Switzerland. The authors thank the Swiss National Science Foundation for financial support through Grants SCOPES, Marie Heim-Voegtlin No. PMPD2–102504 and 200021-100194, as well as NCCR MaNEP project.

Funders	Funder number
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung	PMPD2–102504, 200021-100194

Keywords

Cobaltites
Ionic conductivity
Neutron scattering
Structural phase transition

Access to Document

10.1016/j.physb.2006.01.244

Cite this

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title = "Oxygen order-disorder phase transition in PrBaCo2O5.48 at high temperature",

abstract = "We have investigated the PrBaCo2O5.48 compound by means of neutron powder diffraction at temperatures 300 K < T < 820 K. We observe a new structural phase transition at TOD = 776 K, which we associate with an oxygen order-disorder transition: the well-known room temperature ordered crystal structure, in which slabs of CoO6 octahedra and CoO5 pyramids interleave (Pmmm symmetry) gets lost at temperatures T > TOD, resulting in a statistical distribution of octahedra and pyramids in the sample. The new phase can be described by the tetragonal P 4 / mmm space group. The transition is caused by displacement of apical oxygen ions and is an indication that ionic conductivity, which has been observed in 3D cobaltites, may also exist in layered cobaltites.",

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T1 - Oxygen order-disorder phase transition in PrBaCo2O5.48 at high temperature

AU - Streule, S.

AU - Podlesnyak, A.

AU - Pomjakushina, E.

AU - Conder, K.

AU - Sheptyakov, D.

AU - Medarde, M.

AU - Mesot, J.

PY - 2006/5/1

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AB - We have investigated the PrBaCo2O5.48 compound by means of neutron powder diffraction at temperatures 300 K < T < 820 K. We observe a new structural phase transition at TOD = 776 K, which we associate with an oxygen order-disorder transition: the well-known room temperature ordered crystal structure, in which slabs of CoO6 octahedra and CoO5 pyramids interleave (Pmmm symmetry) gets lost at temperatures T > TOD, resulting in a statistical distribution of octahedra and pyramids in the sample. The new phase can be described by the tetragonal P 4 / mmm space group. The transition is caused by displacement of apical oxygen ions and is an indication that ionic conductivity, which has been observed in 3D cobaltites, may also exist in layered cobaltites.

KW - Cobaltites

KW - Ionic conductivity

KW - Neutron scattering

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