Method of making high Tc oxide superconductor particles by adjusting pH value and cationic ratio of admixed solution followed by drying, heating and firming

This patent describes a method for the preparation of superconducting compositions of the formula MBa2Cu3O7-y wherein M represents yttrium and the rare earth elements and y is an integer ranging from 0.1 to 0.8. It comprises preparing a barium solution in acetic acid, adding the solution to a mixture of copper acetate and a rare earth nitrate, increasing the pH of the resultant solution to a value at which the rare earth and copper hydroxides are formed, forming a viscous gel solution, freeze drying the gel to yield a powder which is heated slowly to a temperature of approximately 600 degrees C. to yield a crystalline resistive phase, and heating the resistive phase in oxygen at a temperature within the range of 750-950 degrees C. to yield a superconducting single phase perovskite