Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/102399
Title: Spin-dependent conductivity of iron-based superconductors in a magnetic field
Authors: Dzyuba, M. O.
Chiang, Yu. N.
Chareev, D. A.
Vasiliev, A. N.
Issue Date: 2015
Publisher: Elsevier
Citation: Spin-dependent conductivity of iron-based superconductors in a magnetic field / M. O. Dzyuba, Yu. N. Chiang, D. A. Chareev, et al. — DOI 10.1016/j.physb.2015.02.004 // Physica B: Condensed Matter. — 2015. — Vol. 464. — P. 68-73. — 308887.
Abstract: We study dc conductivity of iron-based superconductors α-FeSe and LaOFFeAs by measuring the conductance of point-contact heterojunctions in NS and NN modes of transport (N and S denote normal and superconducting states, respectively). In the NS regime, measurements were performed in case of defect-free NS boundary due to shifting it inside the superconductor by the transport current. Under these conditions, we observed the contact conductance to increase at the NS→NN transition driven either by temperature or by magnetic field, and to decrease at the reverse transition. We attribute this effect to the manifestation of spin-dependent nature of the Andreev reflection (spin accumulation) in consequence of the magnetism at the normal side of the NS boundary. Investigating normal conductance in a magnetic field we revealed the nonpersistent hysteresis and square-law dependence of positive magnetoresistance on the magnetic field which fact confirmed this conclusion and pointed to the leading role of itinerant magnetism in the normal ground state of the superconductors studied. Based on the experimental findings and analysis we conclude that there exists a long-range magnetic order in the normal ground state of investigated iron-based superconductors with nematic ferromagnetic exchange interaction between band conduction electrons and local magnetic moments of the ions. © 2015 Elsevier B.V.
Keywords: ANDREEV REFLECTION
FERROMAGNETIC INTERACTION
IRON-BASED SUPERCONDUCTORS
FERROMAGNETIC MATERIALS
FERROMAGNETISM
GROUND STATE
HETEROJUNCTIONS
HIGH TEMPERATURE SUPERCONDUCTORS
IRON
MAGNETIC FIELDS
MAGNETIC MOMENTS
POINT CONTACTS
SUPERCONDUCTING MATERIALS
ANDREEV REFLECTION
FERRO-MAGNETIC INTERACTIONS
FERROMAGNETIC EXCHANGE INTERACTION
IRON-BASED SUPERCONDUCTORS
LOCAL MAGNETIC MOMENTS
LONG RANGE MAGNETIC ORDER
POSITIVE MAGNETORESISTANCE
SUPERCONDUCTING STATE
MAGNETISM
URI: http://hdl.handle.net/10995/102399
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 84925491760
PURE ID: 354982
2dd686e5-d511-44c8-950a-d642f910e8ad
ISSN: 9214526
DOI: 10.1016/j.physb.2015.02.004
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

Files in This Item:
File Description SizeFormat 
2-s2.0-84925491760.pdf272,13 kBAdobe PDFView/Open


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