Transport properties and electronic states of the thermoelectric oxide NaCo_2O_4
arXiv:cond-mat/0207315 · doi:10.1016/S0921-4526(02)01810-0
Abstract
Physical properties of the thermoelectric oxide NaCo_2O_4 are briefly reviewed. The high thermoelectric properties of this material are attributed to the substantially enhanced effective mass, which comes from the large entropy of Co$^{4+}$ in the low spin state. The large entropy confined in the CoO_2 block causes a spin-density-wave transition at 22 K upon Cu substitution for Co, which can be regarded as ``order from disorder''.
4 Pages, $ figures, Proceedings of The 2nd Hiroshima Workshop: Transport and Thermal Properties of Advanced Materials