Single crystals of Tl0.58Rb0.42Fe1.72Se2 are successfully grown with the superconducting transition temperatures Tconset=32K and Tczero=31.4K. The Hall coefficient exhibits a multi-band behavior, which is very similar to that of all other Fe-based superconductors. We found that the susceptibility at the normal state decreases with decreasing the temperature, indicating a strong antiferromagnetic (AFM) spin fluctuation at the normal state, which might be related to the superconductivity (SC). We also determined the upper critical fields in ab-plane and along c-axis. The anisotropy of the superconductivity determined by the ratio of Hc2ab and Hc2c is estimated to 5.0, which is larger than that in (Ba,K)Fe2As2 and BaFe2-xCoxAs2, but smaller than that in cuprate superconductors.
@article{arxiv.1101.0462,
title = {Superconductivity at 32K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals},
author = {Hangdong Wang and Chihen Dong and Zujuan Li and Shasha Zhu and Qianhui Mao and Chunmu Feng and H. Q. Yuan and Minghu Fang},
journal= {arXiv preprint arXiv:1101.0462},
year = {2011}
}