Published in Superconductor Science and Technology
The critical current Ic of single crystals of the iron pnictide superconductor BaFe2(As 1−x P x )2 has been studied through measurements of magnetic hysteresis cycles. We show that the introduction of micrometer-scale irregularities on the surface significantly increases Ic , primarily near the irreversibility magnetic field Hirr . The observed inc...
Published in Superconductor Science and Technology
Owing to the unique double-FeAs-layered structure between neighboring insulating layers, the 12442-type Fe-based superconductors are expected to host rich vortex phenomena in the mixed state. Here, we report a systematic investigation on the influences of quenching treatment and cobalt-doping on the magnetic vortex dynamics of KCa2(Fe 1−x Co x )4As...
Published in Superconductor Science and Technology
Since the discovery of Fe-based superconductors, a lot of effort has been devoted to growing single crystals and epitaxial thin films of them for fundamental studies and applied research of superconductivity. As a result, epitaxial thin films of the most of Fe-based superconductors have been realized. However, some of the materials, namely pristine...
Published in Journal of Physics: Materials
The electronic properties of Fe-based superconductors are drastically affected by deformations on their crystal structure introduced by doping and pressure. Here we study single crystals of FeSe 1−x S x and reveal that local crystal deformations such as atomic-scale defects impact the spectral shape of the electronic core level states of the materi...
Competing interactions in Quantum Materials induce novel states of matter such as frustrated magnets, an extensive field of research both from the theoretical and experimental perspectives. Here, we show that competing energy scales present in the low-dimensional orbital-selective Mott phase (OSMP) induce an exotic magnetic order, never reported be...
Published in Applied Physics A
We have studied theoretically the anisotropic properties of Sommerfeld coefficient and the penetration depth for SmFeAsO1−xFx(x = 0.15) single crystal using the modified phenomenological Ginzburg–Landau (GL) theory for multiband superconducting system. The calculated result of the Sommerfeld coefficient wasfound to be close to that of the experimen...
Published in Frontiers in Physics
High quality single crystals of NdFeAsO0.65F0.35 (the superconducting transition temperature Tc ≃ 30.6 K) were studied in zero-field (ZF) and transverse-field (TF) muon-spin rotation/relaxation (μSR) experiments. An upturn in muon-spin depolarization rate at T ≲ 3 K was observed in ZF-μSR measurements and it was associated with the onset of orderin...
Published in Physics of Metals and Metallography
AbstractDifferent mechanisms of superconductivity result in specific symmetries and structures of the gap in multiband systems. Here we review the spin fluctuation mechanism of Cooper pairing and discuss the spin resonance feature in the superconducting state of iron-based materials.
FeSe is a fascinating superconducting material at the frontier of research in condensed matter physics. Here, we provide an overview of the current understanding of the electronic structure of FeSe, focusing in particular on its low-energy electronic structure as determined from angle-resolved photoemission spectroscopy, quantum oscillations, and m...
Published in Journal of Superconductivity and Novel Magnetism
We investigate the effects of iron content on the upper critical field (Hc2) and the activation energy U(T) in thermally activated flux flow in FexSe0.5Te0.5 near the superconducting transition temperature Tc. The variations in Hc2(T) with temperature are analyzed using Ginzburg-Landau (GL), Werthamer-Helfand-Hohenberg (WHH) models along with the e...
