Nuclear relaxation and electronic correlations in quasi-one-dimensional organic conductors. II. Experiments

In this paper we collect and detail recent results concerning $^{77}$Se and $^{13}$C nuclear relaxation rate measurements obtained on several representatives of the (TMTSF)$_2$X and (TMTTF)$_2$X series of charge transfer salts as a function of temperature and hydrostatic pressure. From the temperature and pressure dependences of $T^{-1}_1$, for the compounds (TMTTF)$_2$PF$_6$, (TMTTF)$_2$Br, (TMTSF)$_2$PF$_6$ and (TMTSF)$_2$ClO$_4$, we are in a position to extract the nature, the amplitude, the statics, the dynamics and finally the dimensionality of spin correlations that characterize the unified phase diagram of both series of materials