Charge localization in organic conductors (TM)

An investigation of the different contributions leading to charge localization in a 1/2 or 1/4 filled band 1D conductor has been conducted through a study of transport properties in the solid solution [ (TMTSF)1-x (TMTTF)x] 2ReO4. The existence of an ordering transition of the anions allows to identify two contributions to the electronic potential with wave vector 4kF. A dominant on-site 4kF potential besides the bond contribution is revealed when Umklapp scattering is pertinent via the weakening of the localization arising at the (0, 1/2, 1/2) anion ordering which is stabilized under pressure in the compound [ (TMTSF) 0.5 (TMTTF)0.5] 2ReO4 at variance with the enhancement of localization observed in the homomolecular (TMTTF)2ReO 4 material