The conductivity of alloyed radical anion salts : 2,5-disubstituted DCNQI's with copper-counterions

2014 We have performed conductivity measurements on a series of binary and ternary copper-salts from differently substituted R, R’ 2014 N, N’-dicyano-quinonediimines (DCNQI’s ). At room temperature they all have a high conductivity, which is preserved partly down to the lowest temperatures. In comparison with the (unalloyed) single complex crystals in these alloys disorder effects shift phase transition temperatures and reduce the magnitudes of the conductivity. In two cases dips of the T-dependent conductivity appear below 50 K. They are explained by a metalsemiconductor transition accompanied by a reentrance into the metallic state at even lower temperatures, in analogy to similar results on (2,5-Me, Me-DCNQI)2Cu under applied pressure. J. Phys. France 50 (1989) 2347-2355 ler SEPTEMBRE 1989, Classification Physics Abstracts 71.30 72.15N