Ion Irradiation Effect on Ba2YCu3O7 Superconductor

Abstract
Single-phased Ba2YCu3O7-y pellets were sequentially irradiated with 200 keV oxygen or nitrogen ions up to 1.5×1016 m-2 at room temperature, and electrical resistance was measured as a function of temperature. The superconducting transition temperature measured with current density greater than 30 kA·m-2 was increased by the ion irradiations to about 3×1015 m-2. The zero-resistance temperature measured with 121 kA·m-2 in current density was enhanced from 88.1–89.1 K to 90.4 K by oxygen ion irradiation to 1.6×1015 m-2, and then reduced to a level obtained in the nonirradiated condition after irradiation to about 1×1016 m-2.