Impact of swift heavy ions on calcium doped YBCO composite thick film

Thick films of Yi_1-xCa_xBa₂Cu₃O_7-δ (YCaBCO) films were prepared by diffusion reaction technique. The non-superconducting inclusions of Y₂O₃ particles were varied in the film and were subjected to irradiation with 200 MeV Ag ions. The films were investigated for structural deformity, electrical and magnetic transport property. Considerable rise of residual and normal state resistivity was noted for irradiated films. A comparative study for magnetization measurement is reported both for YCaBCO and YCaBCO/(5 wt.% and 10 wt. % Y_2O3) composite thick films with and without irradiation. The study revealed an increase in critical current density and flux pinning for irradiated YCaBCO film and un-irradiated 10 wt. % Y₂O₃ composites. However, the marginal decrease of current density and pinning force has been observed for irradiated YCaBCO/10 wt. % Y₂O₃ composite thick film. The pristine one and 5 wt. % added Y₂O₃ and CaBCO records better magnetic performance as compared to irradiated 10 wt. % Y₂O₃ added film. This was explained on basis of controlled defect density with ion irradiation and Y₂O₃ inclusion. Decrease of current density may be interpreted as interaction energy between vortex and defects, synergetic effect of artificial pinning centres and columnar defects, dominates over the pinning energy. (author)