摘要:
To ensure a well-oriented crystal structure, there is provided a process of producing an oxide superconductor of a Y--Ba--Cu--O system with a composition having an atomic ratio Y:Ba:Cu of 1.0-2.0:2.0-2.5:3.0-3.5, the process comprising the steps of: preparing a semimelt including solid and liquid phases and consisting of Y, Ba, Cu and O in the atomic ratio; and solidifying the semimelt to form the oxide superconductor by so controlling a moving speed of a solidification front to have two components of different values in two perpendicularly intersecting directions.
摘要:
A high critical temperature and high critical current density superconductor is disclosed which contains a metal oxide expressed by the following formula (I): (R.sup.1.sub.1-x, Ba.sub.x)Ba.sub.2 Cu.sub.3 O.sub.d (I) wherein R.sup.1 stands for at least one element selected from the group consisting of La, Nd, Sm, Eu and Gd, x is a number greater than 0 but not greater than 0.5 and d is a number between 6.2 and 7.2. Fine phases of RE211, RE422 and/or a metal oxide expressed by the formula (R.sup.2.sub.1-z, Ba.sub.z) (Ba.sub.1-y, R.sup.2.sub.y).sub.2 Cu.sub.3 O.sub.p (R.sup.2 =La, Nd, Sm, Eu or Gd) may be dispersed in a matrix of the matrix phase of the formula (I). The above superconductor may be obtained by cooling a melt having a temperature of 1,000.degree.-1,300.degree. C. and containing R.sup.1, Ba, Cu and O at a cooling rate of 5.degree. C./hour or less under a partial pressure of oxygen of between 0.00001 and 0.05 atm, followed by annealing at 250.degree.-600.degree. C. in an oxygen atmosphere.
摘要:
A composite magnet comprising a core of R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process, enclosed around it with normal conductive or superconductive coil, or a composite magnet including a center of normal conductive or superconductive coil, enclosed around it with ring-shaped R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process is disclosed, which allows easy control of generating magnetic field and gives a relatively strong magnetic field even at a temperature as high as that of liquid nitrogen.
摘要:
A high critical temperature and high critical current density superconductor is disclosed which contains a metal oxide expressed by the following formula (I):(R.sup.1.sub.1-x,Ba.sub.x)Ba.sub.2 Cu.sub.3 O.sub.d (I)wherein R.sup.1 stands for at least one element selected from the group consisting of La, Nd, Sm, Eu and Gd, x is a number greater than 0 but not greater than 0.5 and d is a number between 6.2 and 7.2. Fine phases of RE211, RE422 and/or a metal oxide expressed by the formula (R.sup.2.sub.1-z, Ba.sub.z) (Ba.sub.1-y, R.sup.2.sub.y).sub.2 Cu.sub.3 O.sub.p (R.sup.2 =La, Nd, Sm, Eu or Gd) may be dispersed in a matrix of the matrix phase of the formula (I). The above superconductor may be obtained by cooling a melt having a temperature of 1,000.degree.-1,300.degree. C. and containing R.sup.1, Ba, Cu and O at a cooling rate of 5.degree. C./hour or less under a partial pressure of oxygen of between 0.00001 and 0.05 atm, followed by annealing at 250.degree.-600.degree. C. in an oxygen atmosphere.
摘要:
Disclosed is a method of joining Y-based oxide superconductors on joining two or more Y-based oxide superconductors made by melting process under pressure, characterized by incorporating REBa.sub.2 Cu.sub.3 O.sub.7-.delta. (RE=Y, Ho, Er, Tm or Yb), Ag and BaCuO.sub.2 -CuO type composition to the joining interface as an adhesive phase for joining. It becomes possible to easily make a joined material that does not deteriorate the superconductive characteristic at joined interface.
摘要:
A composite material having a plurality of sections integrated into a unitary structure and each including a bulk of a superconductive metal oxide of RE--Ba--Cu--O wherein RE represents a rare earth element, the bulk of each of the sections having pinning centers and capable of trapping a magnetic field. A first one of the sections has a superconductive current density different from that of a second one of the sections. The composite material may be produced by assembling preformed respective sections into a unitary structure or by immersing one of the sections in a solution to grow crystal of Y--Ba--Cu--O superconductive on that section, followed by trimming.
摘要:
A method of fabrication of an RE-Ba-Cu—O-based oxide superconductor, characterized by using an RE-Ba-O-based compound (RE being one type or two types or more of rare earth elements) and a Ba-Cu-O-based material for liquid phase as a starting material, melting the material for liquid phase, then growing the crystal.
摘要:
A bulk superconductor is produced by subjecting REBa.sub.2 Cu.sub.3 O.sub.y oxide to oxygen annealing after many holes have been formed in the oxide body.
摘要:
The present invention provides a method for joining an RE123 oxide superconductor matrix obtained by a melt process by the use of a solder material. The (110) plane of an RE123 oxide superconductor matrix obtained by a melt process is used as the plane to be joined, a solder material composed of an RE123 oxide superconductor having a lower melting point than the above-mentioned RE123 oxide superconductor is interposed between the planes to be joined, and this solder material is melted and then solidified to form a joining layer, thereby joining the matrices. The solder material can be a sinter, a melt-processed material, a powder, a slurry, or a molded powder.
摘要:
A bulk superconductor including a plurality of units each composed of a substrate and a superconductive layer of R--Ba--Cu--O, where R is selected from La, Nd, Sm, Eu, Gd, Y, Dy, Ho, Er, Tm, Yb and mixtures thereof, formed on the substrate. The units are arranged in a row or in a matrix such that the superconductive layers of respective units are superconductively joined with each other.