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, cilt.100, 2006 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 100 Konu: 7
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1063/1.2357840
  • Dergi Adı: JOURNAL OF APPLIED PHYSICS

Özet

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.