An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure containing rare earth elements, barium (Ba), and copper (Cu). The rare earth elements contain a first element which is praseodymium (Pr), at least one second element selected from the group consisting of neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd), at least one third element selected from the group consisting of yttrium (Y), terbium (Tb), dysprosium (Dy), and holmium (Ho), and at least one fourth element selected from the group consisting of erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

The present invention provides an oxide superconducting bulk magnet which can obtain a sufficient amount of total magnetic flux, by preventing the superconducting bulk body from being broken due to electromagnetic stress and quenching phenomenon to enable magnetization by a strong magnetic field. An oxide superconducting bulk magnet comprising an oxide superconducting bulk body wherein RE.sub.2BaCuO.sub.5 is dispersed in a monocrystalline RE.sub.1Ba.sub.2Cu.sub.3O.sub.y; and an outer peripheral reinforcing ring fitted to the outer periphery of the oxide superconducting bulk body, wherein the outer peripheral reinforcing ring is made of a plurality of metal rings having a multiple ring structure in the radial direction, at least one of the plurality of metal rings has a thermal conductivity of 20 W/(m.Math.K) or more at a temperature of 20 to 70 K and at least one of the plurality of metal rings has a higher strength than the metal ring having a thermal conductivity of 20 W/(m.Math.K) or more.

The present invention relates to a ferrite sintered plate having a composition comprising 47 to 50 mol % of Fe.sub.2O.sub.3, 7 to 26 mol % of NiO, 13 to 36 mol % of ZnO, 7 to 12 mol % of CuO and 0 to 1.5 mol % of CoO, as calculated in terms of the respective oxides, in which the ferrite sintered plate has a volume resistivity of 110.sup.8 to 110.sup.12.Math.cm and a thickness of 10 to 60 m; and a ferrite sintered sheet comprising the ferrite sintered plate on a surface of which a groove or grooves are formed, and an adhesive layer and/or a protective layer formed on the ferrite sintered plate, in which the ferrite sintered sheet has a magnetic permeability at 500 kHz a real part of which is 120 to 800 and an imaginary part of which is 0 to 30, and a product (m) of the real part of the magnetic permeability at 500 kHz of the ferrite sintered sheet and a thickness of the ferrite sintered plate is 5000 to 48000. The ferrite sintered plate and the ferrite sintered sheet according to the present invention have a high volume resistivity as well as a large value and a small value of a magnetic permeability thereof, and therefore can be suitably used as a shielding plate in a digitizer system.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure including rare earth elements, barium (Ba), and copper (Cu). The rare earth elements include a first element which is praseodymium, at least one second element selected from the group consisting of neodymium, samarium, europium, and gadolinium, at least one third element selected from the group consisting of yttrium, terbium, dysprosium, and holmium, and at least one fourth element selected from the group consisting of erbium, thulium, ytterbium, and lutetium. When the number of atoms of the first element is N(PA), the number of atoms of the second element is N(SA), and the number of atoms of the fourth element is N(CA), 1.5(N(PA)+N(SA))N(CA) or 2(N(CA)N(PA))N(SA) is satisfied.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure containing rare earth elements, barium (Ba), and copper (Cu). The rare earth elements contain a first element which is praseodymium (Pr), at least one second element selected from the group consisting of neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd), at least one third element selected from the group consisting of yttrium (Y), terbium (Tb), dysprosium (Dy), and holmium (Ho), and at least one fourth element selected from the group consisting of erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

A superconducting coil of an embodiment includes a superconducting wire including an oxide superconductor layer. The oxide superconductor layer has a continuous Perovskite structure including rare earth elements, barium (Ba), and copper (Cu). The rare earth elements include a first element which is praseodymium (Pr), at least one second element selected from the group consisting of neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd), at least one third element selected from the group consisting of yttrium (Y), terbium (Tb), dysprosium (Dy), and holmium (Ho), and at least one fourth element selected from the group consisting of erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

A composite body of the present invention includes a base and an oxide layer arranged on the base, the oxide layer containing more than 45% by volume of a perovskite-type oxide phase. The composite body may include a first member, a second member, and a joining portion that joins the first member and the second member, at least one of the first member and the second member serving as the base, and the joining portion serving as the oxide layer. The composite body may include the base and a covering portion that covers the whole or part of a surface of the base, the covering portion being formed of the oxide layer.

A superconducting composition of matter including overlapping first and second regions. The regions comprise unit cells of a solid, the first region comprises an electrical insulator or semiconductor, and the second region comprises a metallic electrical conductor. The second region extends through the solid and a subset of said second region comprise surface metal unit cells that are adjacent to at least one unit cell from the first region. The ratio of the number of said surface metal unit cells to the total number of unit cells in the second region being at least 20 percent.

A superconducting material having a strong magnetic-flux pinning by way of sites having high electronic effective mass and charge carrier density. The superconducting material involves a superconducting host material and a dopant pinning material being inert in relation to the superconducting host material and has a {square root over ()}/m* in a range less than that of the superconducting host material, the dopant pinning material doping the superconducting host material.

Disclosed is a (K,Na)NbO.sub.3 (abbreviated by KNN)-based single crystal ceramic. The KNN-based single crystal ceramic according to the present disclosure is formulated by (K.sub.0.5x/2Na.sub.0.5x/2y.sub.y/2M.sub.x+y/2)Nb.sub.1x/3+yO.sub.3, wherein M indicates a metal having a different valence from Na, and indicates a metal vacancy. The above formulated KNN-based single crystal ceramic allows compensating for the volatilization of Na in a growing grain due to the addition of M.sup.2+ ions, and substituting M.sup.2+ ions for Na.sup.+ ions to form metal vacancies, thereby making possible the single crystal growth.