Electron paramagnetic resonance study of the anion ordering in the organic superconductor (TMTSF) 2ClO 4

Abstract

Anion ordering in the tetramethyltetraselenafulvalenium-perchlorate ((TMTSF) 2ClO 4) organic superconductor was manifest in our EPR measurements. Above the anion-ordering temperature, the resonance linewidth showed a linear temperature dependence attributed to torsional-oscillation-induced spin-orbit coupling. On the other hand, it showed a T 3 dependence below the anion ordering, which can be ascribed to spin-orbit coupling in the presence of lattice scattering.