Anisotropy of the Meissner effect and the diamagnetic shielding in (TMTSF)2ClO4

Abstract

The diamagnetic shielding and the Meissner effect measured on a single crystal of (TMTSF)2ClO4 are strongly anisotropic increasing from the a to b* and c* directions. In very low magnetic fields the diamagnetic shielding is complete for all directions. In the a direction the Meissner effect never stands higher than 1% of its expected value whereas it reaches 80 % in the c* direction. The aimantation curves versus magnetic field can be explained by pinning effects, but overestimated values of H c1 are obtained. The Meissner effect and the Ginzburg-Landau parameter for the a direction show that this direction is distinct