| Issue |
J. Phys. IV France
Volume 114, April 2004
|
|
|---|---|---|
| Page(s) | 411 - 417 | |
| DOI | https://doi.org/10.1051/jp4:2004114099 | |
J. Phys. IV France 114 (2004) 411
DOI: 10.1051/jp4:2004114099
Electronic states of a strongly correlated two-dimensional system, Pd(dmit) 2 salts, controlled by uni-axial strain and counter cations
R. Kato1, 1, A. Tajima1, N. Tajima1, A. Nakao1 and M. Tamura11 RIKEN, JST-CREST, 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan
Abstract
The uni-axial strain effects in a series of anion radical
salts,
'-Me
4Z [ Pd(dmit)
2]
2,
'-Et
2Me
2Z[ Pd(dmit)
2]
2 (Z=P, As, Sb) and
Et
2Me
2N[ Pd(dmit)
2]
2 are described. They are classified
into a strongly correlated two-dimensional system. The conduction layer
consists of strongly dimerized Pd(dmit)
2 units forming a distorted
triangular lattice. The electronic structure can be well described by the
dimer model. The half-filled conduction band originates from the HOMO of the
Pd(dmit)
2 molecule. At ambient pressure, these salts are
Mott-insulators where the frustration plays a crucial role. The electronic
state of this system would be governed by the on-site Coulomb energy, the
band width, and the degree of frustration, each of which is sensitive to the
intra- and inter-dimer interactions. The application of uni-axial pressure
induces a variety of physical properties including superconductivity. The
choice of the counter cation affects the electronic state under the
uni-axial strain.
Key words. Pd(dmit)
2 - Uni-axial strain - Resistivity.
© EDP Sciences 2004