Spectroscopic Investigations of Transformation Phenomena Exhibited by Metal-TCNQ Materials

Abstract

The charge-transfer salts of TCNQ with copper and silver exhibit transformation and memory phenomena under the influence of an electric field, a laser beam or an electron beam. These phenomena have been studied in situ by Raman spectroscopy. The initial state was found to be fully ionic, M⁺TCNQ⁻, while the final one is a mixed-valence state containing neutral TCNQ, the untransformed M⁺TCNO⁻ and the corresponding metal. When the irradiation is carried out under controlled conditions continuous metallic regions or well dispersed metallic particles are formed. Various potential applications of these materials are also discussed.