Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/102445
Title: Crystal growth, transport phenomena and two-gap superconductivity in the mixed alkali metal (K1-zNaz)xFe 2-ySe2 iron selenide
Authors: Roslova, M.
Kuzmichev, S.
Kuzmicheva, T.
Ovchenkov, Y.
Liu, M.
Morozov, I.
Boltalin, A.
Shevelkov, A.
Chareev, D.
Vasiliev, A.
Issue Date: 2014
Publisher: Royal Society of Chemistry
Citation: Crystal growth, transport phenomena and two-gap superconductivity in the mixed alkali metal (K1-zNaz)xFe 2-ySe2 iron selenide / M. Roslova, S. Kuzmichev, T. Kuzmicheva, et al. — DOI 10.1039/c3ce42664e // CrystEngComm. — 2014. — Vol. 16. — Iss. 30. — P. 6919-6928.
Abstract: Using the self-flux technique we grew superconducting (K 1-zNaz)xFe2-ySe2 (z = 0.3) single crystals. EDX mapping revealed the uniform elements distribution on the crystal surface while XRD measurements indicate that the crystals are compositionally inhomogeneous on the nanoscale. The physical properties of the as-prepared sample are characterized by electrical resistivity, magnetization and specific heat measurements. Resistivity measurements show the onset of the superconducting transition at 33 K and zero resistivity at 31.7 K. The large upper critical field Hc2(0) was estimated as high as about 140 T for the in-plane field and 38 T for the out-of-plane field. The anisotropy of Habc2(0)/Hcc2(0) and coherence lengths ξab(0)/ξc(0) was found to be around 3.7. The pioneering studies by multiple Andreev reflections effect spectroscopy ("break-junction" technique) revealed the presence of two anisotropic superconducting gaps ΔL = (9.3 ± 1.5) meV, ΔS = (1.9 ± 0.4) meV, and provided a measurement of the ΔL(T) temperature dependence. The Bardeen-Cooper-Schrieffer (BCS) theory ratio ratio for the large gap 2ΔL/kBTbulkc ≈ 6.3 points to a strong electron-boson coupling in the "driving" condensate characterized by the ΔL order parameter. This journal is © the Partner Organisations 2014.
URI: http://hdl.handle.net/10995/102445
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 84904133285
PURE ID: 426745
2645852a-6336-4ffe-9cae-9ae97e3e1d71
ISSN: 14668033
DOI: 10.1039/c3ce42664e
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

Files in This Item:
File Description SizeFormat 
2-s2.0-84904133285.pdf1,02 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.