Abstract
Although successful examples of thermoelectric materials with the "rattler-in-a-cage" structure include filled skutterudites and clathrate compounds, there has been no report on "rattling" oxides. Here we report the thermal properties of defect pyrochlore (β-pyrochlore) oxides with smaller cations in an oversized cage-like crystal structure. It is clearly shown that the thermal diffusivity, α and the thermal conductivity, κ, are lower for the oxides containing lighter A-site cations, contradicting the conventional prediction of the phonon thermal conductivity, in which lighter comprising atoms must give higher α and hence κ. These results strongly suggest that the smaller A-site cations with larger size mismatch to the surrounding cage structure enhance the phonon scattering and thereby reduce α and κ. These findings directly evidence the "rattling" effect of the loosely bound cations on the thermal transport properties of oxide materials.
Original language | English |
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Pages (from-to) | 1299-1302 |
Number of pages | 4 |
Journal | Journal of Electronic Materials |
Volume | 42 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2013 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry