NITROGEN-ION IRRADIATION EFFECT ON BA2YCU3O7 SUPERCONDUCTOR

Single-phased Ba2YCu3O7-y pellets were sequentially irradiated with 200 keV nitrogen ions of 0.3-6.0 x 10(13) m-2.s-1 in a dose rate up to a dose of 2 x 10(16) m-2 at ambient temperature. Electrical resistance was measured as a function of temperature. The superconducting transition temperature, measured with current density greater than 25 kA.m-2 was increased by the ion irradiations. The optimum dose for the enhancement of the zero-resistance temperature was about 1 x 10(14) m-2. The transition temperature, measured with 100 kA.m-2 in current density, was increased from 86.5-87.1 K to 90.9 K by the irradiation with a dose rate of 1.3 x 10(13) m-2.s-1 to 8.4 x 10(13) m-2.