Effect of gamma-irradiation on superconducting transition temperature and resistive transition in polycrystalline YBa2Cu3O(7-delta)

摘要

A bulk polycrystalline sample of YBa2Cu3O(7-delta) (delta approximate to 0.1) has been irradiated by gamma -rays with Co-60 source. Non-monotonic behavior of T-c with increasing irradiation dose Phi (up to about 220 MR) is observed: T-c decreases at low doses (Phi less than or equal to 50 MR) from initial value (approximate to 93 K) by about 2 K and then rises, forming a minimum. At higher doses (Phi greater than or equal to 120 MR) T-c goes down again. The temperature width of resistive transition increases rather sharply with dose below 75 MR and drops somewhat at higher dose. The results observed are discussed, taking into account the granular structure of sample studied and the influence of gamma -rays on intergrain Josephson coupling. [References: 5]