Preparation of a ceramic superconductor from ultrafine particles by freeze-dry process in Ba-Y-Cu-O system

Freeze-dry technique is first reported for preparing ceramic ultrafines. The single-phase complex oxide Ba/sub 2/YCu/sub 3/ O/sub 9/minus/delta/, a poly-crystallized compound, and ceramic superconductor have been synthesized successfully. The experimental results show that not only is the ceramic superconductor obtained uniform with fine particles and excellent superconductivity, but the conditions for solid reactions are relatively limited.