Proton NMR in the organic conductor tetramethyltetraselenafulvalinium hexafluorophosphate

Proton NMR measurements have been made on (TMTSF)2PF6 (di- tetramethyltetraselenafuvalene PF6) at 10 MHz. The linewidth increases below the metal-insulator transition. TMI, indicating the onset of inhomogeneous local fields associated with the appearance of a spin-density wave. The spin-lattice relaxation time T1 increases steeply below TMI. Two minima in T1, at 18 and 60 K, are tentatively associated with changes in the molecular dynamics. © 1981 The American Physical Society.