JPH0312940B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a superconducting material selection method for selecting superconducting materials from ceramic powder, which is a material for oxide-based superconducting ceramics.

[Conventional technology and problems]

Conventionally, in order to improve the superconductivity of ceramic powder or ceramic molded bodies constituting oxide-based superconducting ceramics, a method of changing firing conditions (temperature, atmosphere, number of firing times, etc.) has generally been adopted.

However, this method not only requires a great deal of time and cost, but also fails to produce a good superconducting material in some cases.

Incidentally, in oxide-based superconducting ceramics, a part of the sintered body exhibits superconductivity, and not all of the sintered body exhibits superconductivity.

Therefore, if only those sintered materials that exhibit superconductivity are selected, collected, aggregated, or fired,
Superconductors with higher critical temperatures, critical currents, and critical magnetic fields can be obtained.

This invention was created in view of the above background. The purpose is to efficiently produce superior superconductors by separating ceramic powder into powders that exhibit superconductivity and into multiple groups according to the characteristics of the superconductor (critical temperature, critical current density, critical magnetic field, etc.). The purpose is to propose a method for selecting superconducting materials that can

[Means to solve the problem]

In the method for sorting superconducting materials according to invention 1, a liquid or gas at a temperature below the critical temperature is placed in a container,
A magnetic force is applied from the side, the magnetic force is directed downward and is made stronger, and a mixed powder of superconductors and non-superconductors is introduced into the container from above and allowed to fall.
The present invention is characterized in that the powder having supercurrent properties is separated into a plurality of groups, collected and sorted at a plurality of height positions on the side surface of the container opposite to the one side surface on which the magnetic force is applied. In the sorting method according to the second invention, a liquid or gas having a temperature below the critical temperature is placed in a container, a magnetic force is applied from the side of the container 1, the temperature of the liquid or gas is directed downward, and the temperature is lowered. A mixed powder of a superconductor and a non-superconductor is introduced from above and allowed to fall, forming a plurality of groups of superconducting powder at a plurality of height positions on the side of the container opposite to the one side on which the magnetic force is applied. It is characterized by separation, collection and sorting.

〔Example〕

FIG. 1 shows an embodiment of invention 1,
A medium 2 (liquid or gas) cooled below a critical temperature is placed in a container 1 whose width is narrower than its height. A magnet 3 is arranged on one side of the outside of the container 1, and the strength of the magnetic field is made linearly strong downward as shown in FIG. Also, magnet 3 of container 1
On the opposite side, there are a plurality of chambers partitioned into multiple stages along the vertical direction.

To sort superconducting materials, a mixture 4 of superconducting powder and non-superconducting powder is introduced into the container 1 from above and allowed to fall into the medium 2. The powder 5 having superconductivity (hereinafter referred to as superconducting powder) exhibits diamagnetic properties due to the Meissner effect, and falls in a curved direction in the opposite direction to the magnet 3. Powder 6 that does not have superconductivity (hereinafter referred to as non-superconducting powder) falls vertically without being affected by the magnetic field and accumulates at the bottom of the container.

In this method, the magnetic field is directed downward and is strong, and the better the superconductivity is, the weaker the Meissner effect is. Group of superconducting powders 5-1, 5-2, 5-3
Valve 7 attached to the chamber in a separated state
The non-superconducting material 6 is taken out from the valve 7 at the bottom of the container.

Figure 3 shows an embodiment of the invention of item 2, in which a medium 2 at a temperature below the critical temperature is placed in a container 1 which is narrow in width compared to its height, and the temperature is directed downward in a straight line as shown in Figure 4. It is set at a low temperature. Further, a magnet 3 is arranged on the outside 1 side of the container 1.
On the opposite side, there is a chamber divided into two levels, upper and lower.

When the mixed powders 4 are dropped into this container 1, the superconducting powders 5 are sorted in order of good superconductivity, since the better the superconductivity, the higher the Meissner effect is at the critical temperature.
That is, the powder is divided into groups 5-4 and 5-5, collected in each chamber, and separated from the non-superconducting powder 5 accumulated at the bottom of the container 1.

[Action and effect of the invention]

This invention uses the Meissner effect to separate superconducting powder from non-superconducting powder, but at the same time as sorting, by directing the magnetic force downward to make it stronger or by directing the medium temperature downward to make it lower, superconducting powder can be separated from superconducting powder. Separates and separates powder into multiple groups according to superconductor properties such as critical magnetic field, critical temperature, or critical current density.
It makes it possible to collect.

As described above, this sorting method can separate superconducting powder from non-superconducting powder, and also separate and collect it into groups according to its characteristics. It becomes possible to efficiently obtain superconductors with different temperatures, critical currents, and critical magnetic fields.

[Brief explanation of the drawing]

The drawings show embodiments of the invention.
Figure 1 is a vertical cross-sectional view of an apparatus schematically showing the sorting method of invention 1, Figure 2 is a correlation graph of magnetic field strength and position, and Figure 3 is an apparatus schematically showing the sorting method of invention 2. FIG. 4 is a graph showing the correlation between temperature and position. 1... Container, 2... Medium, 3... Magnet, 4...
Mixture, 5...Superconducting powder, 6...Non-superconducting powder, 7...Valve.

Claims (1)

[Claims] 1. A liquid or gas below the critical temperature is placed in a container, a magnetic force is applied from the side of the container, the magnetic force is directed downward, and the magnetic force is made stronger, and a superconductor and a non-conductor are introduced into the container from above. A mixed powder with a superconductor is introduced and allowed to fall, and the powder having superconductivity is separated into multiple groups and collected at multiple height positions on the side of the container opposite to the one side on which the magnetic force is applied. A method for sorting superconducting materials characterized by sorting. 2. A liquid or gas below the critical temperature is placed in a container, a magnetic force is applied from the side of the container 1, the temperature of the liquid or gas is directed downward to a low temperature, and superconductors and non-superconductors are poured into the container from above. The superconducting powder is separated into multiple groups at multiple height positions on the side of the container opposite to the one side on which the magnetic force was applied.
A method for sorting superconducting materials characterized by collection and sorting.