Abstract
We report the results of RF surface impedance measurements and 77 Se-NMR measurements on improved-quality FeSe. The linewidth of 77 Se-NMR spectrum for the improved FeSe is one third of that for FeSe 0.92 , evidencing the homogeneity of the sample. From the field dependence of the R F surface impedance measurements, the upper critical field H c2 (0) is estimated to be ≈26 T. We also measured nuclear spin–lattice relaxation rate 1/ T 1 in the temperature range of 190–2 K under external magnetic fields of 2, 7, and 16 T. In the normal state below 100 K, 1/ T 1 T shows a Curie–Weiss like temperature dependence, suggesting antiferromagnetic spin fluctuations develop below the structural transition. In the superconducting state, 1/ T 1 S measured at H =2, 7, and 16 T exhibit marked decrease with decreasing temperature due to an opening of the superconducting gap.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
