ANNEALING OF IRRADIATION-INDUCED DEFECTS IN A LASRCUO CRYSTAL

Annealing experiments were performed on a LSCO single crystal irradiat ed with fast neutrons to a fluence of 2.52 x 10(18) n/cm(2). This flue nce increased the critical current density by a factor of 2-3. The sam ple was annealed for a total of 4.5 hours at 200 degrees C and 8 hours at 300 degrees C. It was found that annealing of LSCO has a much less er effect on its critical current density, particularly along the c ax is, compared to YBCO. It is hypothesized that the reduced annealing ef fect is due to the formation of either a more stable interstitial clus ter (compared to the Cu-O cluster in YBCO), or dusters which do not ac t as pinning sites.