High energy heavy ion irradiation damage in oxide superconductor EuBa2Cu3Oy

Defect production and recovery are studied in oxide superconductor, EuBa2Cu 3Oy, irradiated with high energy (80 MeV-3.80 GeV) heavy ions. X-ray diffra ction measurements show that the c-axis lattice parameter increases linearl y with increasing ion-fluence. The rate of the increase in lattice paramete r can be scaled with the primary ionization rate, dJ/dx, and not with the e lectronic stopping power, S-e. This result implies that a Coulomb explosion process triggers the atomic displacements in EuBa2Cu3Oy. From the electric al resistivity change at 100 K as a function of ion-fluence, the diameter a nd the resistivity of a cylindrically-shaped damage region can be determine d. Irradiation induced resistivity change is markedly recovered during the annealing of the specimen up to 300 K. The dJ/dx dependence of the diameter and the resistivity of damaged region is discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved.