Thermoelectric power of HoBaCo2O5.5: possible evidence of the spin blockade in cobaltites.

@article{Maignan2004ThermoelectricPO,
  title={Thermoelectric power of HoBaCo2O5.5: possible evidence of the spin blockade in cobaltites.},
  author={A. Maignan and V. Caignaert and Bernard Raveau and Daniel I. Khomskii and G. Sawatzky},
  journal={Physical review letters},
  year={2004},
  volume={93 2},
  pages={026401}
}
Thermoelectric power measurements have been performed for an ordered oxygen-deficient perovskite, HoBaCo2O5.5, in which the alternative layers of CoO6 octahedra and of [CoO(5)](2) bipyramids are occupied by Co3+ species. The T-dependent Seebeck coefficient S shows a clear change of the conduction regime at the metal-insulator (MI) transition (T(MI) approximately 285 K). The sign change of S from S<0 to S>0 can be explained assuming that a spin state transition occurs at T(MI). In the metallic… CONTINUE READING