Conductive Cu(2,5‐dimethyl‐dicyanoquinonediimine)2 radical ion salts: Systems with none, one, or two phase transitions

摘要: Phase transitions in the radical ion salts of Cu(2,5‐dimethyl‐dicyanoquinonediimine)2 (Cu(DCNQI)2) can be achieved either by ‘‘external’’ pressure or ‘‘internal’’ pressure. The latter is introduced chemical modifications at DCNQI‐molecules (e.g., deuteration) alloying deuterated Cu(2,5‐(CD3)2‐DCNQI)2 (d6) with undeuterated Cu(2,5‐(CH3)2‐DCNQI)2 (h8), giving mixture (h8/d6) different ratios. In this work we present simultaneous conductivity (σ) and electron spin resonance (ESR) experiments on differently Cu(DCNQI)2‐systems alloys under external anticoincidence σ ESR allows determination phase transition temperatures even absence electrical contacts. For each system an individual diagram established. Introducing effective peff=p0+p p0 being (chemical) pressure, a general could constructed determining value for all systems. (h8/...