| 摘要 |
PURPOSE:To obtain the title form by reducing an oxide mixture containing three elements i.e. rare earth one, Ba and Cu in the atom ratio in the final superconductor, enveloping the reduced product with a malleable metal skin and carrying out malleablization together with said skin followed by calcination under an oxidative atmosphere to ensure continuous phase to be retained even in the maleablization. CONSTITUTION:A powdery superconducting precursor consisting of oxides containing rare earth element such as Y, Ba and Cu in the atom ratio: 1/2/3 is heated to 400-1000 deg.C (pref. 500-800 deg.C) to carry out hydrogen reduction. The extent of said reduction may be partial. The resultant superconducting precursor reduced is pref. ground and mixed again and then put into a skin made of highly malleable, oxygen-diffusible metal such as silver or copper. Thence, the resultant powder is malleablized to a desired shape together with said skin and sintered in an oxygen-contg. atmosphere, thus obtaining the objective superconducting malleated form. The sintering is normally carried out at 700-1200 deg.C for 5-100hrs; after that, cooling at a rate of 0.5-3 deg.C/min and retaining at 500 deg.C for several hours. |
