1D Mott localization in organic conductors: An experimental approach

Abstract
In this paper, we present selected results to discuss the 1D Mott localization observed in organic conductors and its influence on the nature of the low temperature magnetic ground state. The approach is essentially experimental and gives an occasion to summarize the work made in Bordeaux during the last twenty years. We first briefly describe the main results concerning the TMTTF salts. Then, we focus the discussion on materials presenting uniform organic stacks to emphasize the relevance of 1/4-Umklapp scattering. Results concerning DMtTTF salts are first described, next the example of the recently studied (EDT-TTF-CONMe ₂)₂AsF ₆ is developed. In both cases, a low T antiferromagnetic ground state is observed, which suggests that the unified phase diagram proposed for the TMTXF series should be generalized, taking into account a progressive loss of centro-symmetry. We finally show how these arguments may rationalize older results found in the TMTTF series. Key words. organic conductors - Mott localization - electronic properties.