Abstract
Reduction of thermal conductivity is essential for obtaining high energy conversion efficiency in thermoelectric materials. We report on significant reduction of thermal conductivity in niobium-doped CaO(CaMnO3)m compounds for thermoelectric energy harvesting due to introduction of extra CaO-planes in the CaMnO3-base material. We measure the thermal conductivities of the different compounds applying the laser flash analysis at temperatures between 300 and 1000K, and observe a remarkable reduction in thermal conductivity with increasing CaO-planar density, from a value of 3.7W·m-1K-1 for m =∞ down to 1.5W·m-1K-1 for m = 1 at 400 K. This apparent correlation between thermal conductivity and CaO-planar density is elucidated in terms of boundary phonon scattering, providing us with a practical way to manipulate lattice thermal conductivity via microstructural modifications.
Original language | English |
---|---|
Article number | 181906 |
Journal | Applied Physics Letters |
Volume | 105 |
Issue number | 18 |
DOIs | |
State | Published - 3 Nov 2014 |
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)