5 7 Fe Mössbauer spectroscopic studies of single-crystalline K x Fe2- y S 2 and K x Fe2- y Se 2
Abstract
We have investigated the physical properties of single-crystalline K x Fe2- y S 2 and K x Fe2- y Se2 samples using 57Fe Mössbauer spectroscopy. The observed 57Fe Mössbauer spectra were reconstructed using a major antiferromagnetic ordered K2Fe4Se5 phase and a minor paramagnetic phase down to 5 K, despite being superconducting below 32.2 K in K x Fe2- y Se2. The analysis of 57Fe Mössbauer spectrum for K x Fe2- y S 2 at 290 K confirms the presence of a major antiferromagnetic ordered K2Fe4 S 5 phase and a minor paramagnetic phase in the K x Fe2- y S 2 single crystal. The derived hyperfine interaction parameters of the paramagnetic phase in K x Fe2- y S 2 suggest that the microstructure of this phase in K x Fe2- y S 2 is similar to that of the superconducting phase in K x Fe2- y Se2 although the K x Fe2- y S 2 single crystals exhibit no superconductivity down to 5 K.
- Publication:
-
Hyperfine Interactions
- Pub Date:
- December 2016
- DOI:
- 10.1007/s10751-016-1278-5
- Bibcode:
- 2016HyInt.237...44T
- Keywords:
-
- Iron-based superconductor;
- Phase separation;
- Mössbauer spectroscopy