Electrical anisotropy in high-Tc granular superconductors in a magnetic field

Item Type: Article
MIUR type: Article > Journal article
Title: Electrical anisotropy in high-Tc granular superconductors in a magnetic field
Authors string: Daghero D.; Mazzetti P.; Stepanescu A.; Tura P.; Masoero A..
University authors:
Referee type: Not specified type
Publisher: APS The Americal Physical Society
Volume: 66
Number: 18
Page Range: 184514-1-184514-10
Number of Pages: 10
ISSN: 1098-0121
Abstract: We propose an analytical model devoted to explain the anisotropy of the electrical resistance observed below the critical temperature in granular high-Tc superconductors submitted to a magnetic field H. Reported experimental results obtained on a YBCO sample show that the superconducting transition occurs in two stages, with a steep drop of the resistance at Tc and a subsequent, smoother decrease. In this second stage, the resistance versus temperature curve is strongly dependent not only on the field intensity, but also on the angle between H and the macroscopic current density j. We start from the assumption that the resistance below Tc is mainly due to the weak links between grains. In the model, weak links are thought of as flat surface elements separating adjacent grains. We calculate the probability for a weak link to undergo the transition to the resistive state as a function of the angle it makes with the external magnetic field H and the macroscopic current density j. In doing this, an important role is given to the strong nonuniformity of the local magnetic field within the specimen, due to the effect of the screening supercurrents flowing on the surface of the grains. Finally, we calculate the electrical resistance of the sample in the two cases H⊥j and H∥j. The predictions of this simple model turn out to be in reasonable agreement with reported experimental results obtained on a YBCO granular specimen
Date: 2002
Status: Published
Language of publication: English
Uncontrolled Keywords:
Departments (original): DIFIS - Physics
Departments: DISAT - Department of Applied Science and Technology
Related URLs:
    Subjects: Area 02 - Scienze fisiche > FISICA DELLA MATERIA
    Area 02 - Scienze fisiche > FISICA SPERIMENTALE
    Date Deposited: 05 Oct 2006 13:57
    Last modification data (IRIS): 15 Oct 2013 11:53:40
    Update date (PORTO): 26 Feb 2015 07:27
    Id Number (DOI): 10.1103/PhysRevB.66.184514
    Permalink: http://porto.polito.it/id/eprint/1403497
    Link resolver URL: Linksolver link

    This field presents the citations number present on Scopus and Web of Science databases e links to the remote records. Also Google Scholar link is present.

    There may be discrepancies with respect to the data in databases for the following reasons:

    • Differences from fields (title, year,...) in UGOV and those in the databases.
    • PORTO citations are extracted monthly. The db is in real time
    • The WoS citation number reflect the collections subscribed by Politecnico (Science citation index Expanded and Conference Proceedings Citation Index)

    For informations contact scrivia/porto



    PDF (1403497) - Postprint
    Document access: Anyone
    Licence: Public - All rights reserved.

    Download (307Kb) | Preview

    Actions (login required)

    View item (admin reserved) View item (admin reserved)

    Document Downloads

    More statistics for this item...