title: Insular superconductivity in a Co-doped iron pnictide CaFe1-xCoxAsF.
abstract: The presence of a macroscopic phase separation between the superconducting and magnetic phases in CaFe1-xCoxAsF is demonstrated by muon spin rotation measurements conducted across their phase boundaries (x=0.05-0.15). The magnetic phase tends to retain the high transition temperature (Tm>Tc), while Co doping induces strong randomness. The volumetric fraction of the superconducting phase is nearly proportional to the Co content x with a constant superfluid density. These observations suggest the formation of superconducting "islands" (or domains) associated with Co ions in the Fe2As2 layers, indicating a very short coherence length.
authors: Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan.
authors: S
authors: S
authors: Takeshita
authors: R
authors: R
authors: Kadono
authors: M
authors: M
authors: Hiraishi
authors: M
authors: M
authors: Miyazaki
authors: A
authors: A
authors: Koda
authors: S
authors: S
authors: Matsuishi
authors: H
authors: H
authors: Hosono