2012/03/07 by Vadim Grinenko, V. Grinenko, Grinenko, V. +24
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con) #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1203.1585
6 pages, 4 figures (including supplement)
arxiv created 2012/03/07 · openalex publication_date 2012/03/07 · arxiv updated 2012/03/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
High-quality KFe2As2 single crystals have been studied by transport, magnetization and low-T specific heat measurements. Their analysis shows that superconductivity occurs (in some cases coexists) in the vicinity of disordered magnetic phases (Griffiths and spin-glass type) depending of the amount of local magnetic moments (probably excess Fe derived)and sample inhomogeneity. The achieved phenomenological description of our data including also data from the literature provides a consistent explanation of the observed non-Fermi-liquid behavior and of the nominally large experimental Sommerfeld coefficient gamman about 94 mJ/mol K2. We suggest that the intrinsic value (directly related to the itinerant quasi-particles) gammael about 60(10)mJ/mol K2 is significantly reduced compared with gamman. Then an enhanced relative jump of the electronic specific heat Delta Cel/gammael Tc about 0.8 and a weak total electron-boson coupling constant lambda less or about 1 follow.