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200 MeV Ag+15 ion irradiation created columnar defects and enhanced critical current density of La-2125 type superconducting thin films

K. R. Mavani·D. S. Rana·S. Rayaprol·R. N. Parmar·D. G. Kuberkar·Ravi Kumar·M. Tonouchi·J. John·R. Nagarajan
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Abstract

We have deposited c-axis oriented thin films of La1.5Dy0.5CaBa2Cu5Oz (La-2125) tetragonal superconductor on LaAlO3 (001) by Pulsed Laser Deposition. These films were irradiated with 200 MeV Ag+15 ions. Atomic Force Microscopy and Elastic Recoil Detection Analysis indicate that the irradiation has created columnar defects along the entire thickness (2000 A) of these films. With ion irradiation up to 1*10^11 ions/cm2, the critical current density (Jc(H)) is found to enhance by almost five folds, which is attributed to the augmented flux pinning by the columnar defects. A further increase in irradiation to 1*10^12 ions/cm2 causes reduction in Jc(H) due to distorted morphology of the film. Our work shows that the enhancement in Jc (H) of the irradiated La-2125 film is comparable to that in irradiated RE-123. Also, as the La-2125 type films have greater chemical stability than RE-123 (RE = rare earth ion), La-2125 type superconductors are potential candidates for applications. Interesting to note that there are partial flux jumps observed to occur symmetrically in the magnetic hysteresis of irradiated La-2125 thin films with enhanced Jc(H).

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K. R. Mavani, D. S. Rana, S. Rayaprol, R. N. Parmar, D. G. Kuberkar, Ravi Kumar, M. Tonouchi, J. John, R. Nagarajan. 2006-08-09. 200 MeV Ag+15 ion irradiation created columnar defects and enhanced critical current density of La-2125 type superconducting thin films. https://doi.org/10.1016/j.ssc.2007.03.027

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