Processing YBa sub 2 Cu sub 3 O sub x wires in O sub 3 /O sub 2

Plastically extruded wires were heat treated in O{sub 2} or a mixture of O{sub 2}/3% O{sub 3}. The presence of O{sub 3} during the burnoff of organics resulted in measurable increases in critical current density(J{sub c}), while post-sintering annealing in the O{sub 3}/O{sub 2} mixture rather than in O{sub 2} had no effect. Maximum zero-field J{sub c} values exceeded 1000 A/cm{sup 2}. 14 refs., 1 fig., 1 tab.