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.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 2009
- DOI:
- 10.1103/PhysRevLett.103.027002
- Bibcode:
- 2009PhRvL.103b7002T
- Keywords:
-
- 74.70.Ad;
- 74.25.Jb;
- 76.75.+i;
- Metals;
- alloys and binary compounds;
- Electronic structure;
- Muon spin rotation and relaxation