TRANSIENT PERSISTENT SWITCHING OF CU-DCNQI BY LIGHT AND PRESSURE

In Cu(2,5-DMe-DCNQI)(2) (DCNQI:N,N'-Dicyanoquinonediimine) crystals wi th metal-like conductivity, phase transitions to an insulating state c an be induced by deuteration (internal pressure) and external pressure . A reentry to the metallic state at lower temperature is observed in alloyed Cu-DCNQI systems. The ESR-silence during metallic conductivity is lifted in the insulating state. The correlation of ESR and conduct ivity allows a quantitative detection of the gradual onset of the phas e transition. Because of large hysteresis effects of sigma- and ESR-me asurements, switching by light and pressure is possible. These feature s point to prospective application for molecular electronic devices as cystalline (2,5-DMe-DCNQI)(2)Cu films represent, due to the crystal s tructure, conducting networks in molecular dimensions switchable from a 3-d to an 1-d conductivity behaviour. This might be realized spatial ly resolved in nanostructures if electron beam lithography is applied.