Thermoelectric properties of the Kondo semiconductor: Yb _{1 x} Lu _{x}B _{12}
Abstract
We have measured electrical resistivity ρ, thermal conductivity κ, and thermopower S of the Kondo semiconductor Yb _{1 x}Lu _{x}B _{12} (0⩽ x⩽1). On increasing x to 0.05, both the semiconducting increase in ρ( T) and the enhancement of κ below 60 K are strongly suppressed. A giant negative peak in S( T) for x=0 at 10 K vanishes already at x=0.01, whereas a broad peak stays at 30 K for x⩽0.25 and shifts to 100 K for x⩾0.75. These results suggest that the energy gap in YbB _{12} is filled up by the development of a midgap state at the Fermi level with Lu substitution.
 Publication:

Journal of Magnetism and Magnetic Materials
 Pub Date:
 May 2001
 DOI:
 10.1016/S03048853(00)006272
 Bibcode:
 2001JMMM..226..137I