Radiation effects in bulk samples of high Tc superconductors YBa2Cu3O(6+delta) and GdBa2Cu3O(6+delta)

The above high-temperature superconductors, both with delta of 1 or less and with Tc of about 92 K, were irradiated with 67.5-MeV electrons at fluences of 10 to the 13th, 10 to the 14th, 10 to the 15th, and 5 x 10 to the 15th electrons/sq cm. After each irradiation, the resistance versus temperature curves were measured using the four-probe resistance technique. Negligible changes in the superconductng transition temperature were seen.