Nuclear magnetic resonance, electron paramagnetic resonance and magnetization
measurements show that bulk LixβZnPc are strongly correlated one-dimensional
metals. The temperature dependence of the nuclear spin-lattice relaxation rate
1/T1β and of the static uniform susceptibility ΟSβ on approaching room
temperature are characteristic of a Fermi liquid. Moreover, while for xβ2 the electrons are delocalized down to low temperature, for xβ4 a
tendency towards localization is noticed upon cooling, yielding an increase
both in 1/T1β and Οsβ. The x-dependence of the effective density of
states at the Fermi level D(EFβ) displays a sharp enhancement for xβ2, at the half filling of the ZnPc lowest unoccupied molecular orbitals. This
suggests that LixβZnPc is on the edge of a metal-insulator transition where
enhanced superconducting fluctuations could develop.Comment: 5 pages, 4 figure