Local magnetization measurements of the organic superconductor κ-(BEDT-TTF)2Cu(NCS)2

In the organic superconductor κ-(TTF) 2 Cu(NCS) 2 , the dynamic relaxation rate (R) of the magnetization curves is investigated using a micro Hall probe in the field perpendicular to the two-dimensional conduction layer. R shows a characteristic dip-like minimum in a narrow field region where the second magnetization peak on the increasing branch appears. This behavior of R indicates the existence of an intermediate state between the ordered and disordered vortex phases.