NORMAL-STATE PROPERTIES OF ET ORGANIC CONDUCTORS

We study quasi-2D organic conductors particularly kappa-(ET)(2)Cu[N(CN )(2)]Br and kappa-(ET)(2)Cu[N(CN)(2)]Cl in which the Fermi surface exh ibits nesting properties. The nesting induces specific properties. In particular, it leads to a spin density wave (SDW) ground state below a critical pressure. The phase diagram is obtained within a mean field theory. Nesting properties lead to important effect of antiferromagnet ic fluctuations on the normal state. It may explain the abnormal tempe rature dependence of the observed NMR spin-lattice relaxation rate. To discuss these effects in our calculation, we use an analytical disper sion relation which fits the Fermi surface determined by band structur e calculations.