Journal
PHYSICAL REVIEW B
Volume 85, Issue 16, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.85.165145
Keywords
-
Funding
- CNRS IDRIS [1842]
- CRIHAN [2007013]
Ask authors/readers for more resources
We used fully correlated ab initio calculations to determine the effective parameters of Hubbard and t-J models for the thermoelectric misfit compound Ca3Co4O9. As for the NaxCoO2 family, the Fermi level orbitals are the a(1g) orbitals of the cobalt atoms; the e'(g) being always lower in energy by more than 240 meV. The electron correlation is found very large U/t similar to 26 as well as the parameters fluctuations as a function of the structural modulation. The main consequences are a partial a(1g) electrons localization and a fluctuation of the in-plane magnetic exchange from antiferromagnetic to ferromagnetic. The behavior of the Seebeck coefficient and the figure of merit are discussed in view of the ab initio results, as well as the 496 K phase transition.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available