A fundamental behavior on mechanical contacts of YBCO bulks

Koichiro Sawa, Masako Suzuki, Masaru Tomita, Masato Murakami

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


A persistent current switch (PCS) is a key component for superconducting magnetic energy storage (SMES) system. In past research on a mechanical PCS, a metallic superconductor made of Nb and NbTi is used as a switching material. However, recently the research on SMES coil of a high temperature superconductor (HTS) is widely carried out, in which a PCS is also expected to work in liquid nitrogen temperature. In this paper, yttrium barium copper oxide (YBCO) bulk of HTS was proposed as a switch material, and the test on the fundamental characteristics of a mechanical contact between two YBCO bulks was carried out. As a result, a switching phenomenon between low and high resistance ranges was observed at a threshold current value in the V-I characteristics of the YBCO contact. Furthermore, the tests indicate that a certain amount of current needs to flow before the switching phenomenon. Because the discontinuous transition occurred after the surface-insulating layer formed by degradation of YBCO was destroyed due to current effect in the contact area.

Original languageEnglish
Pages (from-to)803-808
Number of pages6
JournalPhysica C: Superconductivity and its applications
Issue numberPART 1
Publication statusPublished - 2002 Oct 1
Externally publishedYes


  • Mechanical contact
  • Persistent current switch
  • Superconducting magnetic energy storage
  • YBCO

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


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