Heavy-ion irradiation dependence of the superconducting properties of (Cu,C)Ba2Ca3Cu4O10.5−δ

Abstract

To enhance or improve critical currents density (Jc) and irreversibility field (Hirr) of (Cu,C)Ba2Ca3Cu4O10.5−δ ((Cu,C)-1234), pinning centers were introduced by heavy-ion irradiation. The polycrystalline samples were irradiated with Au15+ ions (240 MeV energy) at various fluence of 1×1011, 2.5×1011 and 5×1011 ions/cm2. Jc and Hirr were determined for the irradiated samples as well as unirradiated samples. Jc (77 K, 1 T) increase from 3.9×104 A/cm2 to 4.1×106 A/cm2 for at fluence of 1×1011 ions/cm2 of heavy-ion irradiated sample and decreases with further increase of fluence. These results indicate the possibility of further enhancement of Jc and of achieving a very high Hirr of (Cu,C)-1234 below a fluence of 1×1011 ions/cm2.