Longitudinal sound velocity of the organic superconductor κ-(BEDT-TTF)2Cu(NCS)2 single crystals is measured near the superconducting transition as a function of temperature and magnetic field up to 8 T. The sound velocity shows a remarkable decrease below the superconducting transition. The shape of the anomaly is step-like and the amount of its relative change at Tc is -3.8X10-4 in the absence of magnetic field. The sound velocity shows a softening around 3 T. The position of the sound velocity minimum depends on the frequency. This behavior is discussed based on the vortex dynamics.
ASJC Scopus subject areas
- 化学 (全般)