Method for preparing rare earth-barium-cuprate pre-ceramic resins and superconductive materials prepared therefrom

This patent describes a method of making a pre-ceramic material capable of being converted into an electrically superconductive ceramic material having the general formula ABa2CU3O7-x where A is a rare earth metal and x is from 0 to 0.5. It comprises: refluxing stoichiometric amounts of a first solution comprising a rare earth isopropoxide and barium isopropoxide in isopropanol under a dry, inert atmosphere; adding to the first solution a stoichiometric amount of a second solution comprising copper ethylhexanoate in isopropanol; refluxing the first and second solutions to obtain a precipitate; adding to the precipitate a quantity of a first solvent comprising water and isopropanol having from about 2 to 10 equivalents of water per mole of rare earth isopropoxide to hydrolyze the precipitate and to sufficiently dissolve the precipitate to produce a substantially homogeneous solution; concentrating the homogeneous solution by removing a sufficient amount of the first solvent to produce a viscous or dry pre-ceramic resinous material; softening or dissolving the pre-ceramic resinous material in a second solvent comprising a nonpolar solvent or alcohol and a nonpolar solvent to obtain a desired viscosity; and forming the viscous pre-ceramic material into the desired product shape