The vortex state in a single crystal of the layered organic superconductor κ-(BEDT- TTF)2 Cu(NCS) 2, where BEDT-TTF (or ET) is bis(ethylenedithio) tetrathiafulvalene, was studied by H-NMR 1. Under a low field region around 0.75 T, the vortex-glass-liquid transition was demonstrated by a diverging of the longitudinal nuclear spin relaxation rate and peak broadening in spectra. Under a high field region near the upper critical field Hc2 (0)7 T, the curvature of nuclear spin relaxation curves showed a drastic change at the temperature where the emergence of the quantum vortex slush state was reported. The mechanism in this curvature change was discussed in terms of the fluctuating field produced by fragments of vortex glass.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2007 7月 11|
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