Electron-spin-echo experiments on the one-dimensional conductor[(fluoranthene)2]+[(PF6)x(SbF6)1−x]− (x≈0.5)

The electron-spin-echo decay function was determined for the conducting phase of [(C16H10)2]+X- in the temperature range 183-300 K. The decay function exhibited an exp[-(γt)3/2] dependence, characteristic of one-dimensional spin diffusion. The ratio 5×106≤D∥/D⊥≤5×108 for the inner-stack-to-out-of-stack diffusion rates was determined from the characteristic time t0, at which the electron-spin-echo decay function changed to the "conventional" exp(-2γ′τ)) form. The deduced value 2×1013≤D∥≤2×1016 rad/s is consistent with the bulk dc conductivity and with recently determined nuclear spin-lattice relaxation rates. The overall assumption of highly mobile electronic spins was confirmed by an Overhauser-type experiment.