Syntheses of Gd₂BaCuO₅ (Gd211) precursor powders for Gd-Ba-Cu-O bulk superconductor

Different preparation techniques of Gd211 powders have been studied. The Gd211 powders prepared by three different processes were calcined at different temperatures between 860°C and 960°C. The single phase of Gd211 was formed above 900°C. With calcined temperature increasing, the carbon content of the Gd211 powders reduced, but the Gd211 particle size increased, and the particles being spherical in shape at low calcined temperature became more anomalous. Study of the three preparation processes indicated that the coprecipitation process is complex. But the particles of Gd211 powders prepared by it are fine and homogeneous. The carbon content of the Gd211 powders is small. So the coprecipitation process is the best preparation process of Gd211 powders in the three preparation process.