2008/07/02 by Oded Millo, Itay Asulin, Ofer Yuli +8
Materials Science · Physics and Astronomy · #Computer science #Iron-based superconductors research #Rare-earth and actinide compounds #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.78.092505
published as Phys. Rev. B 78, 092505 (2008)
arxiv created 2008/07/02 · openalex publication_date 2008/09/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report a scanning tunneling spectroscopy investigation of polycrystalline SmFeAsO0.85 having a superconducting transition at 52 K. On large regions of the sample surface the tunneling spectra exhibited V-shaped gap structures with no coherence peaks, indicating degraded surface properties. In some regions, however, the coherence peaks were clearly observed and the V-shaped gaps could be fitted to the theory of tunneling into a d-wave superconductor, yielding gap values between 8 and 8.5 meV corresponding to the ratio 2\ensuremathΔ/KBTC\ensuremath∼3.55--3.8, which is slightly above the BCS weak-coupling prediction. In other regions the spectra exhibited zero-bias conductance peaks consistent with a d-wave order-parameter symmetry.