CERAMIC SUPERCONDUCTOR AND PRODUCTION THEREOF

• Main Authors: SASAKI TAKAHIKO, KIKUTA TOSHIO, SHISHIDO NORIYOSHI, TOYODA NAOKI, UKEI KAZUTOSHI, FUKUDA TSUGUO
• Format: Patent
• Language: English
• Published: 23.06.1989
• Subjects: ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CABLES; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; CONCRETE; CONDUCTORS; ELECTRICITY; INORGANIC CHEMISTRY; INSULATORS; LIME, MAGNESIA; METALLURGY; REFRACTORIES; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; SLAG; TREATMENT OF NATURAL STONE

PURPOSE:To obtain the subject superconductor outstanding in resistance to moisture and thermal stress, with high critical temperature and critical current density, by constituting a specific composition from rare earth metals, alkali (alkaline earth) metals copper and noble metal elements or compounds containing these elements. CONSTITUTION:Elements represented by R, A and Cu are weighed and mixed as element themselves or compounds containing them so as to satisfy the formula [R is rare earth metal; A is alkali (alkaline earth) metal; B is noble metal element selected from Ru, Rh, Pd, Ag, Re, Os, Ir, Pt, Au, Fe, Co and Ni; 0<=alpha,beta,delta<0.1; 0.03<=gamma<=0.6; 0<=epsilon<1] followed by calcination in air, O2 or pressurized O2 of <=200kg/cm at 600 to 1,000 deg.C. Thence, the product is ground and the resultant powder is incorporated with 1-3wt. times ratio of a flux compound (e.g., CuO) followed by packing the resultant blend in a vessel made from an allow of at least one kind of element selected from the above-mentioned B, and carrying out heating treatment at 950-1,100 deg.C in the same atmosphere as that mentioned above followed by annealing at a rate of <=20 deg.C/hr, thus obtaining the objective superconductor having rhombic crystal structure consisting of composition of the formula.