Ion irradiation dependence of the superconducting properties of (Cu,C)Ba 2Ca 3Cu 4O 10.5− δ

Abstract

To further enhance the critical current density ( J c) and irreversibility field ( H irr) of (Cu,C)Ba 2Ca 3Cu 4O 10.5− δ (hereafter described as (Cu,C)-1234), pinning centers were introduced by heavy-ion irradiation. Polycrystalline samples were irradiated with Au 15+ ions (240 MeV energy) or Xe 14+ ions (200 MeV energy) at a fluence of 10 11 ions/cm 2. J c (77 K, 1 T) shows a remarkable increase from 3.9 × 10 4 to 4.1 × 10 6 A/cm 2 for Au 15+ ion irradiated sample and increase from 3.9 × 10 4 to 1.5 × 10 5 A/cm 2 for Xe 14+ ion irradiated sample. The value of H irr(77 K) is about 12.5 T for Au 15+ ion irradiated sample and for Xe 14+ ion irradiated sample, peak effect like behavior was observed at 77 K. Ion irradiation is much effective to introduce pinning centers in (Cu,C)-1234 and to control or optimize J c and H irr values of (Cu,C)-1234. These results indicate the possibility of further enhancement of J c and reaching a high H irr for (Cu,C)-1234.