NMR evidence for very slow carrier density fluctuations in the organic metal (TMTSF)${}_2$ClO${}_4$

Abstract

We have investigated the origin of the large increase in spin-echo decay rates for the ${}^{77}$Se nuclear spins at temperatures near to $T=30K$ in the organic superconductor (TMTSF)${}_2$ClO${}_4$. The measured angular dependence of $T_2^{-1}$ demonstrates that the source of the spin-echo decays lies with carrier density fluctuations rather than fluctuations in TMTSF molecular orientation. The very long time scales are directly associated with the dynamics of the anion ordering occurring at $T=25K$, and the inhomogeneously broadened spectra at lower temperatures result from finite domain sizes. Our results are similar to observations of line-broadening effects associated with charge-ordering transitions in quasi-two dimensional organic conductors.

5 pages, 4 figures

References in corpus (3)

• Charge ordering in the TMTTF family of molecular conductors
• The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors
• Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors

Cited by in corpus (3)

• Coexistence of Superconductor and Spin-Density Wave in (TMTSF)2ClO4: Spatial Structure of the Two-phase State
• ${}^{77}$Se NMR investigation of the field-induced spin-density-wave transitions in (TMTSF)${}_2$ClO${}_4$
• NMR Evidences for the coupling between conduction electrons and molecular degrees of freedom in the exotic member of the Bechgaard salt, (TMTSF)2FSO3