Abstract
We report the low-temperature electronic and magnetic properties of the alkali metal-organic solvent intercalated iron selenide superconductor Li(C5H5N)(0.2)Fe2Se2 using muon-spin-spectroscopy measurements. The zero-field muon spin relaxation (mu SR) results indicate that nearly half of the sample is magnetically ordered and spatially phase separated from the superconducting region. The transverse-field mu SR results reveal that the superfluid density of Li(C5H5N)(0.2)Fe2Se2 is two dimensional in nature. The temperature dependence of the penetration depth lambda (T) can be explained using a two-gap s-wave model. This implies that, despite the 2D nature of the superfluid density, the symmetry of the superconducting gap remains unaltered to the parent compound FeSe. DOI: 10.1103/PhysRevLett.110.137003