MgB2 polycrystalline superconducting specimens were irradiated with 10 MR and 20 MR doses of γ-rays. An increase in the normal state resistance and a broadening of the resistive transition to the superconducting state were observed with increasing γ-irradiation dose within the temperature range of 28 -31 K. The change in the critical temperature, T c was found to be insignificant after irradiation. The critical current density, Jc was found to be enhanced almost at all temperatures after irradiation. The enhancement of Jc was found to be linear with the irradiation dose at all temperatures. These results are explained by the effects of γ-rays and temperature on the migration of MgO impurities into the grains and the oxygen segregation in the grain boundaries.
ASJC Scopus subject areas
- Physics and Astronomy(all)