| 摘要 |
The invention relates to methods for producing oxidic powders having a carbon content of < 200 ppmw, a hydrogen content of < 150 ppmw and a composition which can yield a high-temperature superconductor after further processing. Said oxidic powders are made from powder-like oxide precursors which can be processed into formed pieces and possibly also to high-temperature superconductive sintered bodies. The powder particles of the oxide precursor are largely isolated, fed to a substantially vertical tubular reactor, passed through the reactor from top to bottom against the flow of a gas and thermally decomposed in the process. Alternatively the oxidic powder or the formed pieces made therefrom are treated with an acid which is added as an acid, especially to the furnace atmosphere, or as a thermally decomposable salt. The added acid and/or the acid released during thermal decomposition of the salt contributes to the removal of carbon and/or hydrogen. The invention further relates to the corresponding mixed oxides and high-temperature superconductors. |
