Superconductive alloys having bifurcated critical current density and

Abstract

A device having superconductive and resistive states including an element comprising a high temperature superconductive material having a first (high) state with a first (high) critical current density and having a second (low) state with a second (low) critical current density, wherein the second (low) critical current density is less than the first (high) critical current density. A transient pulse generator applies a transient pulse to the element. The transient pulse changes the state of the element between the first (high) and second (low) states, the element being superconductive in the first (high) state, and the element being resistive in the second (low) state. A YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.7-x -Ag compound exhibiting bifurcation of its critical current density versus temperature curve. A process for the production of a YBa.sub.2 Cu.sub.3 O.sub.7-x or YBa.sub.2 Cu.sub.3 O.sub.7-x -Ag superconducting material which exhibits bifurcation in its critical current density versus temperature curve. The process involves the provision of the appropriate powder or mix of powders, pressing the powder to form the desired specimen, sintering the specimen at a sufficient temperature for a sufficient time to achieve fusion of the powder, heat treating the sintered specimen, and subjecting the specimen to an oxygenation process.