Abstract
Using fine powders prepared by a freeze-drying process of a nitrate solution, a YBa2Cu3O7-x superconductor has been successfully formed in a ceramic plate. The other processes employed are two heat treatments, a flash decomposition of the freeze-dried nitrates and a subsequent calcination. It has been found that the formation of high-quality ceramics requires ∼10% of the Cu nitrate to be added to the stoichiometric nitrate solution as a starting material of the freeze-drying process. The ceramics thus obtained have the characteristics of a very dense structure with large grains and exhibit magnetic properties as a high Tc superconductor as good as those of a monocrystalline YBa2Cu3O7-x.