We report a study of the organic compound (TMTSF)2ClO4 in both a sample cooled very slowly through the anion ordering temperature (relaxed state) and a sample cooled more rapidly (intermediate state). For the relaxed state the entire sample is observed to be superconducting below about T_c ~ 1.2 K. The second moment of the internal field distribution was measured for the relaxed state yielding an in-plane penetration depth of ~ 12000 Angstroms. The intermediate state sample entered a mixed phase state, characterized by coexisting macroscopic sized regions of superconducting and spin density wave (SDW) regions, below T_c ~ 0.87 K. These data were analyzed using a back-to-back cutoff exponential function, allowing the extraction of the first three moments of the magnetic field distribution. Formation of a vortex lattice is observed below 0.87 K as evidenced by the diamagnetic shift for the two fields in which we took intermediate state data.
@article{arxiv.cond-mat/0301241,
title = {Muon Spin Rotation study of the $(TMTSF)_2ClO_4$ system},
author = {A. J. Greer and D. R. Harshman and W. J. Kossler and A. Goonewardene and D. Ll. Williams and E. Koster and W. Kang and R. N. Kleiman and R. C. Haddon},
journal= {arXiv preprint arXiv:cond-mat/0301241},
year = {2009}
}