Current-Induced Low-Resistance State and Its Crystal Structure of a TTF-Based Dimeric Donor Salt

Abstract

A bromide salt of a TTF-based cross-cyclophane-type donor displayed characteristic nonlinear voltage-biased conductivity. As the applied voltage was increased, the passing current was enhanced abruptly at 54 kV·cm^-1, exhibiting hysteretic behavior. X-ray analysis of the current-induced low-resistance state of the crystal, which has P4₁ symmetry, revealed that the degree of charge disproportionation of the dimeric donor in the crystal substantially decreased during the current application. This result is interpreted as indicating that the class I mixed-valence state of the cation-radical salt of the dimeric donor was converted into the class III state by the application of the large current.