We report measurements of the Seebeck coefficients of boron carbides having compositions B12+xC−x, 0.15 <x < 1.7, from 6 to 900 K. These Seebeck coefficients are large, ≈200 μV/K at 300K, despite boron carbides having high carrier densities, ≈ 1021cm−3. The Seebeck coefficients also have unusual temperature dependencies and depend only weakly on carrier density. These exceptional properties can arise from boron carbides’ bipolaronic holes substantially softening the vibrational modes with which they interact.
|Number of pages||4|
|Journal||Physical Review Letters|
|State||Published - Sep 14 1998|