"Pudding mold" band drives large thermopower in Na$_x$CoO$_2$

Kazuhiko Kuroki; Ryotaro Arita

doi:10.1143/JPSJ.76.083707

"Pudding mold" band drives large thermopower in Na$_x$CoO$_2$

Materials Science 2009-11-13 v1

Authors: Kazuhiko Kuroki , Ryotaro Arita

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Abstract

In the present study, we pin down the origin of the coexistence of the large thermopower and the large conductivity in Na $_x$ CoO $_2$ . It is revealed that not just the density of states (DOS), the effective mass, nor the band width, but the peculiar {\it shape} of the $a_{1g}$ band referred to as the "pudding mold" type, which consists of a dispersive portion and a somewhat flat portion, is playing an important role in this phenomenon. The present study provides a new guiding principle for designing good thermoelectric materials.

Keywords

thermopower Na$_x$CoO$_2$ pudding mold band electronic structure thermoelectric materials density of states

Cite

@article{arxiv.0705.3088,
  title  = {"Pudding mold" band drives large thermopower in Na$_x$CoO$_2$},
  author = {Kazuhiko Kuroki and Ryotaro Arita},
  journal= {arXiv preprint arXiv:0705.3088},
  year   = {2009}
}

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