THERMAL-STABILITY AND ANNEALING OF COLUMNAR DEFECTS IN BI2SR2CA1CU2O8AG SUPERCONDUCTOR/

This work establishes the stability at elevated temperatures of column ar defects, artificially formed in the Bi-based cupric oxide supercond uctor Bi2Sr2Ca1Cu2O8 for enhanced vortex pinning. Isochronal anneals, conducted in air, led to losses of critical current density in two sta ges. The defects were relatively stable up to similar to 550 degrees C , where second stage annealing began; above this, the pinning diminish ed rapidly. The recrystallization and loss of columnar defects were co rroborated by transmission electron microscopy. (C) 1995 American Inst itute of Physics.