Synergetic effect of 200 MeV Ag ions and Y₂0₃ inclusions on critical current density in Y_1-xCa_xBa₂Cu₃O_{7- d} thick film

Y_1-xCa_xBa₂Cu₃O_7-ä (x=0.1)+Y₂O₃ (10wt.%) composite thick film prepared by diffusion reaction technique is irradiated with 200 MeV Ag ions. Micro Raman reveals the microstructural changes. Beans critical state model was employed to calculate the critical current density estimated from the width of magnetization loops obtained at 40 K. The enhancement of J_c from 1.4×10⁴Acm⁻² to 6.7×10⁴ Acm⁻² with irradiation upto fluence 5×10¹¹ions-cm⁻² in YCaBCO samples is observed indicating that flux pinning increases due to the creation of columnar defects induced by irradiation. Addition of Y₂0₃ increases the J_c in the pristine sample to 8.3×10⁴ Acm⁻² but decreases with increasing fluence. The insulating inclusions Y₂O₃ causes J_c increment by the process of flux pinning. Combined effects of inhomegenity and columnar defects due to irradiation have degraded the superconducting volume. The interaction energy between vortex and defects dominate over the pinning energy. Hence the pinning sites are not used effectively and J_c starts decreasing with irradiation.