Enhancing the pinning strengths in polycrystalline MgB₂

Abstract

The dependence of the critical current density, J c , on the gamma irradiation dose in MgB 2 polycrystalline superconducting specimens has been studied. The MgB 2 samples were irradiated with 10 MR and 20 MR doses of γ-rays. The critical current density, J c was found to be enhanced almost at all temperatures after irradiation. The enhancement of J c was found to be linear with the irradiation dose at all temperatures. We also report on the correlation between the superconducting transition temperature and the residual resistivity ratio. Most of our results agree with the Testardi and Mooij rules which suggest that the dominant pairing mechanism of MgB 2 is the phonon-mediated interaction.

Applications of YBCO-coated conductors: a focus on the chemical solution deposition method

“…Introducing artificial pinning centers in the HTSCs using several types of energetic radiation was found to be very successful at increasing the vortex pinning forces. [11][12][13][14][15][16][17][18][19][20] Irradiating the HTSCs with heavy ions 12,13,20 creates extended structural (columnar) defects in the material. Because the columnar defects can pin a vortex along its whole length, they are considered to be effective vortex pinning sites (even at high temperatures).…”