A method of producing polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950? C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000? C. for up to 72 hours. The polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y thus produced is in the form of elongated crystals having an average length of 2 to 10 ?m and an average width of 1 to 2 ?m, and embedded with spherical nanoparticles of yttrium deficient Y.sub.3Ba.sub.5Cu.sub.8O.sub.y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.

A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-? and a nano-structured, preferably nanowires, WO.sub.3 dopant in a range of from 0.01 to 3.0 wt. %, preferably 0.075 to 0.2 wt. %, based on total material weight. Methods of making the superconductor may preferably avoid solvents and pursue solid-state synthesis employing Y, Ba, and/or Cu oxides and/or carbonates.

Operational characteristics of an extremely low resistance (ELR) film comprised of an ELR material may be improved by depositing a modifying material onto appropriate surfaces of the ELR film to create a modified ELR film. In some implementations of the invention, the ELR film may be in the form of a c-film. In some implementations of the invention, the ELR film may be in the form of an a-b film, an a-film or a b-film. The modified ELR film has improved operational characteristics over the ELR film alone or without the modifying material. Such operational characteristics may include operating in an ELR state at increased temperatures, carrying additional electrical charge, operating with improved magnetic properties, operating with improved mechanic properties or other improved operational characteristics. In some implementations of the invention, the ELR material is a mixed-valence copper-oxide perovskite, such as, but not limited to YBCO. In some implementations of the invention, the modifying material is a conductive material that bonds easily to oxygen, such as, but not limited to, chromium.

A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-? and a nano-structured, preferably nanowires, WO.sub.3 dopant in a range of from 0.01 to 3.0 wt. %, preferably 0.075 to 0.2 wt. %, based on total material weight. Methods of making the superconductor may preferably avoid solvents and pursue solid-state synthesis employing Y, Ba, and/or Cu oxides and/or carbonates.

This disclosure relates to compounds of formula (I):

L.sub.nD.sub.m(B.sub.xB.sub.1-x).sub.r(Z.sub.tZ.sub.1-t).sub.qM.sub.pA.sub.y(I),

in which n, m, x, r, t, q, p, L, D, B, B, Z, Z, M, and A are defined in the specification. These compounds can exhibit superconductivity at a high temperature.

A high temperature superconducting joint, a high temperature superconducting wire or tape comprising a high temperature superconducting joint, or an MRI or NMR machine comprising a high temperature superconducting wire or tape comprising a high temperature superconducting joint. Also, methods for producing a high temperature superconducting joint for use in a superconducting wire or an MRI or NMR machine, or other high field generating coil.

An energy storage device includes multiple bulk superconductor rings and at least one superconductor wire coil between the multiple bulk superconductor rings. The multiple bulk superconductor rings and the at least one superconductor wire coil are interconnected to define a closed geometric shape.

A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-? and a nano-structured, preferably nanowires, WO.sub.3 dopant in a range of from 0.01 to 3.0 wt. %, preferably 0.075 to 0.2 wt. %, based on total material weight. Methods of making the superconductor may preferably avoid solvents and pursue solid-state synthesis employing Y, Ba, and/or Cu oxides and/or carbonates.

There is set forth herein a superconducting lead assembly comprising: a positive superconducting wire; a negative superconducting wire, wherein the positive superconducting wire is configured to conduct inflow current to a cryogenic apparatus and wherein the negative superconducting wire is configured to conduct outflow current away from the cryogenic apparatus; and an electrically insulating separator, wherein the positive superconducting wire and the negative superconducting wire are arranged proximately one another and on opposite sides of the electrically insulating separator for cancellation of electromagnetic forces attributable to current flowing simultaneously in opposite directions within the positive superconducting wire and the negative superconducting wire, and wherein a length of the superconducting lead assembly is flexible. In one embodiment the positive superconducting wire and the negative superconducting wire can include high temperature superconducting (HTS) material.

A superconducting material includes YBa.sub.2Cu.sub.3O.sub.7-? and a nano-structured, preferably nanowires, WO.sub.3 dopant in a range of from 0.01 to 3.0 wt. %, preferably 0.075 to 0.2 wt. %, based on total material weight. Methods of making the superconductor may preferably avoid solvents and pursue solid-state synthesis employing Y, Ba, and/or Cu oxides and/or carbonates.