Paste compositions for additive manufacturing and methods for the same are provided. The paste composition may include an organic vehicle, and one or more powders dispersed in the organic vehicle. The organic vehicle may include a solvent, a polymeric binder, a thixotropic additive, and a dispersant. The organic vehicle may be configured to provide the paste composition with a suitable viscosity. The organic vehicle may also be configured to provide a stable paste composition for a predetermined period of time.

An oxide superconductor according to an embodiment includes an oxide superconducting layer includes a single crystal having a continuous perovskite structure containing at least one rare earth element selected from the group consisting of yttrium, lanthanum, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, barium, and copper, containing praseodymium in a part of the site of the rare earth element in the perovskite structure, and having a molar ratio of praseodymium of 0.00000001 or more and 0.2 or less with respect to the sum of the at least one rare earth element and praseodymium; fluorine in an amount of 2.0×10.sup.15 atoms/cc or more and 5.0×10.sup.19 atoms/cc or less; and carbon in an amount of 1.0×10.sup.17 atoms/cc or more and 5.0×10.sup.20 atoms/cc or less.

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.

An oxide superconductor includes: REBa.sub.2Cu.sub.3O.sub.7-x (RE being one element selected from a “RE element group” of Pr, Nd, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The RE includes at least three, types of metallic elements (M1, M2, and M3), and the three types of metallic elements are any element of the RE element group selected in order. In an oxide system satisfying R(1)≦20 mol % and R(M2)≧60 mol % and R(M3)≦20 mol %, R(M1) being an average metallic element ratio of M1 in M1+M2+M3, SD(Ms)>0.15 is satisfied at a position at 50% of an average film thickness of a cross section including the c-axis, Ms being the metallic element of not larger of R(M1) and R(M3), SD(Ms) being a standard deviation/average value of a concentration of Ms.

An oxide superconductor has a composition expressed by RE.sub.aBa.sub.bCu.sub.3O.sub.7-x, where RE represents one rare earth or a combination of two or more of a rare earth, a satisfies 1.05≦a≦1.35, b satisfies 1.80≦b≦2.05, and x represents an amount of oxygen deficiency, and a non-superconducting phase having an outer diameter of 30 nm or less is included in a superconducting phase.

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).

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.

A process for producing a process for producing a LnM.sub.2Cu.sub.3O.sub.x high-temperature superconductive powder, the process comprising: i) providing an aqueous solution of Ln, M and Cu and at least one mineral acid; ii) adding at least one sequestrating agent and, optionally, at least one dispersant to the solution to form a precipitate; iii) recovering the precipitate from the solution; and iv) heating the precipitate in a flow of oxygen to form the LnM.sub.2Cu.sub.3O.sub.x powder, wherein Ln is a rare earth element, preferably Y, Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Sc, Yb, or a mixture of two or more thereof, and wherein M is selected from Ca, Sr, and Ba.

A method for producing a solid composition according to the present disclosure is a method for producing a solid composition that is used for forming a functional ceramic having a first crystal phase. The method for producing a solid composition includes: producing an oxide composed of a second crystal phase different from the first crystal phase; and mixing the oxide and an oxo acid compound.

The present disclosure relates to a method for preparing high-temperature superconducting yttrium barium copper oxide (YBCO) wire by 3D-printing, this method is divided into the following four steps: firstly, preparing a nano-level superconducting powder precursor; and then, preparing a printing paste with suitable viscosity and supporting characteristics; after that, using a CAD 3D modeling, exporting STL format model data and slicing by a professional software; implementing one-step preparing strands with low AC loss by twisting the print nozzle. Finally, the printed twisted wire is formed into a practical superconducting twisted cable through the processes such as plastic removal process, crystallizing process, oxygen supplementing process and assembling process in order. The present disclosure firstly provides an application for applying high temperature superconducting material to direct ink writing 3D-printing technology. By preparing micro/nano level superconducting core filaments based on 3D-printing, the diameter of the core filaments could be reduced, and thereby a material-structure integrative design could be implemented. The present disclosure simplifies the preparation of high temperature superconducting wires, improves the current-carrying capacity and the production efficiency of the high temperature super conducting wires, and reduces the production cost.