J. Phys. IV France 114 (2004) 319
Reexamination of the phase diagrams of and -type systemsC. Hotta
IRIKEN, Condensed Molecular Materials Laboratory 2-1, Hirosawa, Wako, 3510198 Saitama, Japan
We propose new phase diagrams of the ground states of and -type organic materials according to our calculations on the extended Hubbard-type model of the anisotropic triangular lattice structure. The relevance to the previously presented experimental phase diagrams are discussed. We argue that the metal-insulator transitions are driven by the change in the anisotropy of band structure as well as by the change in the bandwidth. Both of them vary by the application of pressure, together governing the density of states near the Fermi level. Key words. phase- phase-anosotropic triangular lattice-extended Hubbard model-MI transition.
© EDP Sciences 2004