https://doi.org/10.1140/epjb/e2004-00179-8
Sign change of the thermoelectric power in LaCoO3
Laboratoire CRISMAT, UMR 6508 CNRS ISMRA, 6 boulevard Maréchal Juin, 14050 CAEN Cedex 4, France
Corresponding author: a antoine.maignan@ismra.fr
Received:
3
February
2004
Revised:
26
April
2004
Published online:
29
June
2004
The substitution of 1%-Ce4+ for La3+ in LaCoO3 is found to
change the sign of the Seebeck coefficient at room temperature. This
demonstrates that not only holes but also electrons can be created in
LaCoO3. The result is compatible with the Heikes formula for doping
levels close to the “pure” trivalent Co3+ state. Nonetheless, the
physical properties such as magnetic susceptibility, magnetization, thermal
conductivity and resistivity are found to be asymmetric for hole and
electron-doped LaCoO3. Such a different behaviour is ascribed to the
very different spin-states of Co4+ (low-spin,
and Co2+ (high-spin, 
.
PACS: 72.15.Jf – Thermoelectric and thermomagnetic effects / 75.30.Et – Exchange and superexchange interactions / 71.38.-k – Polarons and electron-phonon interactions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
