New phase line in the mixed state of Nb/NbZr multilayers

Tsutomu Nojima, Taisuke Masuda, Shigeru Nakano, Yoshinori Kuwasawa

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


The superconducting multilayer Nb/NbZr is known to show an upturn feature in the parallel upper critical field Hc2|(T) at a characteristic temperature T+ with decreasing T. This phenomenon occurs due to the change of the position for nucleation of order parameter Δ(r) from Nb to NbZr layers. In order to understand the behavior of the localized Δ(r) in the mixed state, we have measured the critical current density J c of Nb/NbZr as a function of H and of angle between H and film plane. In this system, the peak effect has been reported in Jc(H) above T+ by previous work. In this work, besides this peak, two kinds of kink structures in Jc(H) are observed at fields HL1 and HL2 only in the temperatures above T+.HL1(T) and HL2(T) are plotted around the extrapolated line from Hc2|(T) above T+. From the field dependence of the angular derivative of Jc and the discussion about the free energy in the system, we will show the possibility of the phase transition at these characteristic fields.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Society of Photo-Optical Instrumentation Engineers
Number of pages8
ISBN (Print)0819414522, 9780819414526
Publication statusPublished - 1994
Externally publishedYes
EventSuperconducting Superlattices and Multilayers - Los Angeles, CA, USA
Duration: 1994 Jan 241994 Jan 25

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherSuperconducting Superlattices and Multilayers
CityLos Angeles, CA, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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