Pulsed ESR Studies on Low Dimensional Organic Conductors

The temperature dependence of the electron spin relaxation times T1e and T2e in the radical anion salt (2, 5-DMe-DCNQI) 2 Li can be explained by a smooth transition from motional narrowing to spin exchange. In addition a phase transition at 60 K leads to spin pairing and relaxation. With further decreasing temperature the correlation time of the spin motion becomes longer to reach at 40 K the inverse Larmor frequency w -1 L (r = 10-10 s). Therefore below 35 K T1e and T2e are no longer equal in magnitude: at 4.5 K T1e increases to ~ 1500 ns and T2e decreases to ~ 70 ns.