We investigate the low temperature magnetic field dependence of the resistivity in the thermoelectric misfit cobalt oxide [Bi1.7Ca2O4]0.59CoO2 from 60 K down to 3 K. The scaling of the negative magnetoresistance demonstrates a spin dependent transport mechanism due to a strong Hund's coupling. The inferred microscopic description implies dual electronic states which explain the coexistence between localized and itinerant electrons both contributing to the thermopower. By shedding a new light on the electronic states which lead to a high thermopower, this result likely provides a new potential way to optimize the thermoelectric properties.
@article{arxiv.0811.0498,
title = {Dual electronic states in thermoelectric cobalt oxide},
author = {Patrice Limelette and Sylvie Hebert and Herve Muguerra and Raymond Fresard and Charles Simon},
journal= {arXiv preprint arXiv:0811.0498},
year = {2008}
}