Kazushi Kanoda

Comparative study on the magnetism and conductivity of (DI-DCNQI)2M, (M=Li, Cu, Ag)

Abstract The electronic state of a new group of DCNQI-Metal complexes, (DI-DCNQI) 2 M (M=Li, Cu, Ag), has been studied by the electric resistance, R , magnetic susceptibility, χ, 1 H- and 13 C-NMR measurements. The newly synthesized complexes, (DI-DCNQI) 2 Ag and (DI-DCNQI) 2 Li, are paramagnetic insulators below room temperature. An antiferromagnetic ordering was found at least in the Ag salt. This is the first case, in the DCNQI-Metal complexes, that the π electrons on the DCNQI molecules exhibit an antiferromagnetic state. The insulating state of the Ag salt is considered as a Mott insulator associated with freezing of 4 k F charge density wave. The Cu salt of the DI-system is known to be metallic down to low temperatures. The hybridization of the 3 d orbitals of Cu ions with the LUMO of DI-DCNQI is demonstrated by the measurements of temperature dependence of χ and Kight shift of 1 H- and 13 C-NMR on the cyano site.

Carrier doping to (DCNQI)2Li

Abstract The alloy systems, (DMe-DCNQI) 2 Li 1−x Cu x , have been investigated with the aim of controlling of the electronic state by doping of Cu ions into the (spin-) Peierls insulator, (DMe-DCNQI) 2 Li. Light doping (x 0.5), the systems are metallic down to at least 1.5K. It is found that the values of ( T 1 T ) −1 of 13 C-NMR in the high temperature region (T>100K) change systematically with doping concentration, x .

13C-NMR Study of Mott Insulating Phase in κ-(BEDT-TTF)2X Family

Abstract The κ-(BEDT-TTF)2X family are quite attractive in the study of metal-insulator transitions and competition between superconductivity and magnetic ordering. We report 13C-NMR study of X= Cu[N(CN)2]Cl salt and discuss on the electronic structure, compared with the results of superconducting salts. In addition, we found that the deuterated Cu[N(CN)2]Br salt, when cooled rapidly, showes AF ordering like the Cu[N(CN)2]Cl salt with only minor fraction of superconducting phase. We also report 13C-NMR study of this salt.