Widenmeyer, Marc ; Checchia, Stefano ; Xiao, Xingxing ; Scavini, Marco ; Weidenkaff, Anke (2020)
Effects of Nanodomains on Local and Long-Range Phase Transitions in Perovskite-Type Eu0.8Ca0.2TiO3–δ.
In: Nanomaterials, 10 (4)
doi: 10.3390/nano10040769
Artikel, Bibliographie
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Kurzbeschreibung (Abstract)
The determination of reversible phase transitions in the perovskite-type thermoelectric oxide Eu0.8Ca0.2TiO3–δ is fundamental, since structural changes largely affect the thermal and electrical transport properties. The phase transitions were characterized by heat capacity measurements, Rietveld refinements, and pair distribution function (PDF) analysis of the diffraction data to achieve information on the phase transition temperatures and order as well as structural changes on the local level and the long range. On the long-range scale, Eu0.8Ca0.2TiO3–δ showed a phase transition sequence during heating from cubic at 100 < T < 592 K to tetragonal and finally back to cubic at T > 846 K. The phase transition at T = 592 K (diffraction)/606 K (thermal analysis) was reversible with a very small thermal hysteresis of about 2 K. The local structure at 100 K was composed of a complex nanodomain arrangement of Amm2- and Pbnm-like local structures with different coherence lengths. Since in Eu0.8Ca0.2TiO3–δ the amount of Pbnm domains was too small to percolate, the competition of ferroelectrically distorted octahedra (Amm2 as in BaTiO3) and rigid, tilted octahedra (Pbnm as in CaTiO3) resulted in a cubic long-range structure at low temperatures.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2020 |
| Autor(en): | Widenmeyer, Marc ; Checchia, Stefano ; Xiao, Xingxing ; Scavini, Marco ; Weidenkaff, Anke |
| Art des Eintrags: | Bibliographie |
| Titel: | Effects of Nanodomains on Local and Long-Range Phase Transitions in Perovskite-Type Eu0.8Ca0.2TiO3–δ |
| Sprache: | Englisch |
| Publikationsjahr: | 16 April 2020 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Nanomaterials |
| Jahrgang/Volume einer Zeitschrift: | 10 |
| (Heft-)Nummer: | 4 |
| DOI: | 10.3390/nano10040769 |
| URL / URN: | https://doi.org/10.3390/nano10040769 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | The determination of reversible phase transitions in the perovskite-type thermoelectric oxide Eu0.8Ca0.2TiO3–δ is fundamental, since structural changes largely affect the thermal and electrical transport properties. The phase transitions were characterized by heat capacity measurements, Rietveld refinements, and pair distribution function (PDF) analysis of the diffraction data to achieve information on the phase transition temperatures and order as well as structural changes on the local level and the long range. On the long-range scale, Eu0.8Ca0.2TiO3–δ showed a phase transition sequence during heating from cubic at 100 < T < 592 K to tetragonal and finally back to cubic at T > 846 K. The phase transition at T = 592 K (diffraction)/606 K (thermal analysis) was reversible with a very small thermal hysteresis of about 2 K. The local structure at 100 K was composed of a complex nanodomain arrangement of Amm2- and Pbnm-like local structures with different coherence lengths. Since in Eu0.8Ca0.2TiO3–δ the amount of Pbnm domains was too small to percolate, the competition of ferroelectrically distorted octahedra (Amm2 as in BaTiO3) and rigid, tilted octahedra (Pbnm as in CaTiO3) resulted in a cubic long-range structure at low temperatures. |
| Freie Schlagworte: | perovskite, europium, titanium, oxide, local structure, pair distribution function, synchrotron diffraction, Rietveld refinements, phase transitions |
| Zusätzliche Informationen: | This article belongs to the Special Issue Synchrotron Radiation Techniques for the Investigation of Nanomaterials |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Werkstofftechnik und Ressourcenmanagement |
| Hinterlegungsdatum: | 20 Mai 2020 07:14 |
| Letzte Änderung: | 03 Jul 2024 02:44 |
| PPN: | |
| Projekte: | The support by Claudio Ferrero and Mauro Coduri (European Synchrotron Radiation Facility, Grenoble, France) and Tobias Kohler, Daniel Plaz, and Timo Mahnkopf during the collection of the synchrotron diffraction data is highly acknowledged., Songhak Yoon (Fraunhofer IWKS, Hanau, Germany) is thanked for the discussions on the diffraction data., The authors are grateful for the help of Konstantin Skokov (Technical University of Darmstadt, Department of Materials and Earth Sciences, Functional Materials, Darmstadt, Germany) collecting the low-temperature Cp data by PPMS. |
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Effects of Nanodomains on Local and Long-Range Phase Transitions in Perovskite-Type Eu0.8Ca0.2TiO3–δ. (deposited 26 Aug 2020 13:41)
- Effects of Nanodomains on Local and Long-Range Phase Transitions in Perovskite-Type Eu0.8Ca0.2TiO3–δ. (deposited 20 Mai 2020 07:14) [Gegenwärtig angezeigt]
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