Spin resonance of an organic conductor: Tetramethyltetrathiafulvalene tetracyanoquinodimethane

Evaluation of the magnetic gaps of the (TMTTF) and (TCNQ) stacks with the help of the temperature dependence of the measured g-values leads to the conclusion that the (TCNQ) stack is driving the metal-insulator transition. The relative sizes of the magnetic gaps on the (TMTTF) and (TCNQ) stacks are compatible with the existence of only one phase transition. A comparison with (TTF)(TCNQ) is made and the lower transition temperature observed for (TMTTF)(TCNQ) is in agreement with the smaller gap observed in this compound for the (TNNQ) stack. © 1976.