TMTSF relaxation rates below

Figure 6 (a) Resistivity [after Ref. 47] and (b) EPR spin susceptibility of (TMTTF)2X compounds [after Ref. 46] undergoing a one-dimensional Mott-Hubbard localization below 7p (c) electron spin susceptibility of (TMTSF)2PF6 [after Ref. 38] (d) plot of the l3C spin lattice relaxation rate versus 7xf(7) for three compounds in the TM2X series. The temperature below which the charges are localized is indicated by 7p. No localization is observed for Se compounds (dashed line) above the SDW or SC ordering. (From Ref. 41b.)... 

The search for a field dependence of the nuclear relaxation rate in the normal phase of (TMTSF)2C104 has been set out by Caretta et al. [74]. Their results obtained at 200 K (Fig. 13) up to 15 Tesla show a square-root field dependence which is indicative of one-dimensional diffusive spin dynamics. The square root dependence is cut off at low enough field due to processes that do not conserve spin along the stacks [66]. The field dependence is found to become essentially undetectable around 150 K and below, which may indicate either a change of dimensionality in the spin dynamics or that the collisionless regime is reached. 

Nuclear spin-lattice relaxation conducting regime. As for the spin sector in the conducting regime, an approach to the 1-D exponent can be attempted looking at the spin-lattice relaxation rate for which the 2k° contribution should become predominant at low temperature where 0deviation from linearity below 150 K or so (Fig. 11), signaling the onset of 2k fluctuations. These AF fluctuations become even more visible when T, is plotted... 

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