Johanning, Melanie ; Porz, Lukas ; Dong, Jinfeng ; Nakamura, Atsutomo ; Li, Jing-Feng ; Rödel, Jürgen (2020)
Influence of dislocations on thermal conductivity of strontium titanate.
In: Applied Physics Letters, (117)
doi: 10.1063/5.0010234
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Recently, several creative processing techniques yielded thermoelectrics with reduced thermal conductivity and, thereby, an enhanced figure or merit. These were based on engineered complex microstructures with attendant dislocation structures. In this study, we implement highly controlled mesoscopic dislocation structures into the model thermoelectric SrTiO3 in order to quantify phonon scattering at dislocations. Both single crystals and polycrystalline material have been furnished with enhanced dislocation densities increased by a factor of 150–300 by plastic deformation. Thermal conductivity was measured using laser flash analysis between room temperature and 325°C. Etch pit techniques and ultra-high voltage electron microscopy afford quantification of dislocation density. Experimental results were compared to predictions by the Debye-Callaway model. The latter revealed that dislocation densities of 1015 m-² would be necessary for the reduction of thermal conductivity of SrTiO3 in the investigated temperature range, which could not be realized using the plastic deformation mechanism applied.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2020 |
| Autor(en): | Johanning, Melanie ; Porz, Lukas ; Dong, Jinfeng ; Nakamura, Atsutomo ; Li, Jing-Feng ; Rödel, Jürgen |
| Art des Eintrags: | Bibliographie |
| Titel: | Influence of dislocations on thermal conductivity of strontium titanate |
| Sprache: | Englisch |
| Publikationsjahr: | 14 Juli 2020 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Applied Physics Letters |
| (Heft-)Nummer: | 117 |
| DOI: | 10.1063/5.0010234 |
| Kurzbeschreibung (Abstract): | Recently, several creative processing techniques yielded thermoelectrics with reduced thermal conductivity and, thereby, an enhanced figure or merit. These were based on engineered complex microstructures with attendant dislocation structures. In this study, we implement highly controlled mesoscopic dislocation structures into the model thermoelectric SrTiO3 in order to quantify phonon scattering at dislocations. Both single crystals and polycrystalline material have been furnished with enhanced dislocation densities increased by a factor of 150–300 by plastic deformation. Thermal conductivity was measured using laser flash analysis between room temperature and 325°C. Etch pit techniques and ultra-high voltage electron microscopy afford quantification of dislocation density. Experimental results were compared to predictions by the Debye-Callaway model. The latter revealed that dislocation densities of 1015 m-² would be necessary for the reduction of thermal conductivity of SrTiO3 in the investigated temperature range, which could not be realized using the plastic deformation mechanism applied. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Nichtmetallisch-Anorganische Werkstoffe |
| Hinterlegungsdatum: | 30 Jul 2020 05:17 |
| Letzte Änderung: | 30 Jul 2020 05:17 |
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