Thermoelectric and magnetic properties of nanocrystalline La0.7Sr0.3CoO3

O. J. Dura (Korresp. Autor*in), Peter Franz Rogl, Matthias Falmbigl, Gerfried Hilscher, Ernst Bauer

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed

Abstract

This work reports on the effect of grain size on the electrical, thermal, and magnetic properties of La0.7Sr0.3CoO3 samples obtained by solid-state reaction combined with ball milling. Electrical characterization made for samples with grain sizes ranging from 26 nm to 0.57 mu m shows a size-induced metal-to-insulator transition for the sample with smallest grain size. As a consequence of the grain size reduction, there is a change of the thermopower sign and the thermal conductivity displays extremely low values. Interestingly, the thermoelectric figure of merit displays an enhancement as a consequence of the grain size reduction. The Curie temperature was found to be constant whereas the saturation magnetization decreases as grain size decreases. Thereby electrical and magnetic properties of nanocrystalline samples are interpreted in terms of a core-shell structure in which grain boundaries display an insulating behavior while the core region of each grain exhibits the bulk properties.
OriginalspracheEnglisch
FachzeitschriftJournal of Applied Physics
Jahrgang111
Ausgabenummer6
DOIs
PublikationsstatusVeröffentlicht - 2012

ÖFOS 2012

  • 104017 Physikalische Chemie

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