Observations of a hysteresis loss valley in yttrium barium copper oxide superconductors

Celebi S., Ozturk A., Kolemen U., LeBlanc M. A. R.

JOURNAL OF APPLIED PHYSICS, vol.100, no.7, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 100 Issue: 7
  • Publication Date: 2006
  • Doi Number: 10.1063/1.2357840
  • Journal Name: JOURNAL OF APPLIED PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Yozgat Bozok University Affiliated: No

Abstract

We present measurements of the ac susceptibility of sintered yttrium barium copper oxide pellets prepared by a melt processed solid state reaction method, with different amounts of ZnO added. The measurements were performed versus temperature T for several different ac magnetic field amplitudes H-ac in the presence of static bias magnetic fields H-b directed along H-ac. For all our samples, for each choice of H-ac, the imaginary part of the ac susceptibility versus T traces a peak, denoted by chi"(max), centered at a temperature denoted by T-max.We also find that plots of the values of chi(")(max) vs H-ac and of chi(max) vs T-max generate curves that display a valley. Calculations of hysteresis losses, exploiting a critical-state model where the critical current density j(c)=alpha(T)/B-n, reproduce the experimental data quite well. (c) 2006 American Institute of Physics.