Alloy superconductor and methods of making the same

Abstract

There are provided an intermetallic-compound superconductor that is high in superconducting transition temperature, and an alloy superconductor that is high in superconducting transition temperature and excels in malleability and ductility, as well as a method of making such a superconductor with good reproducibility and at a low cost of manufacture. This entirely new intermetallic compound superconductor is made of magnesium (Mg) and beryllium (Be) and has a chemical composition expressed by formula: Mg1Be2, has a hexagonal AlB2 type crystallographic structure and has a superconducting transition temperature (Tc) of 35 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (Tc) of 35 K and being low in specific resistance for normal conduction at a temperature ranging from the superconducting transition temperature to a room temperature. In the method of manufacture, a Mg containing feedstock powder and a Be containing feedstock powder are mixed together to form a mixture thereof which is, e.g., hot pressed to produce a semiconductor product.

Description

[0001]This application is a divisional of U.S. patent application Ser. No. 10 / 469,245, filed on Sep. 8, 2003, which is a 371 of International Application No. PCT / JP02 / 02205 filed on Mar. 8, 2002 which claims the priority of Japanese Application No. 2001-067663, filed on Mar. 9, 2001, all of which are incorporated herein by reference.TECHNICAL FIELD[0002]This present invention relates to an intermetallic-compound superconductor and an alloy superconductor which can be utilized in superconducting electronics such as a large scale electric power transmission system, a superconductive power storage system, a high performance Josephson device and a high frequency electronic device, and which especially are high in superconducting transition temperature, are easy to manufacture, excel in malleability and ductility, and yet are altogether new. The invention also relates to a method of making such a novel superconductor.BACKGROUND ART[0003]Superconductors are known to include a superconduct...

AI Technical Summary

Benefits of technology

The present invention provides an alloy superconductor with a composition of MgBexBy, where x and y are numbers between 0 and 20. The alloy has a high superconducting transition temperature of 35 K and a low specific resistance at temperatures between its superconducting transition temperature and room temperature. It can be used as a superconductor in various applications such as electric power transmission and electronic components. The method of manufacturing the alloy involves mixing powders of Mg, Be, and B, shaping them into a pellet, and heating or hot pressing them under pressure and in an inert gas to form the alloy. The method allows for the production of reproducible and easily manufacturable alloy superconductors.

Problems solved by technology

A simple metal superconductor may contain a simple metal such as Pb and Nb but is known to lack utility because it is low in superconducting transition temperature.

These intermetallic compound superconductors include one with Nb3Ge which is relatively high in superconducting transition temperature (=about 23 K), but commonly have the disadvantage that they are weak in distortion and are fragile.

As such the extreme complexity of the crystallographic structure of a composite oxide superconductor makes it difficult to conduct its production in a large volume and with good reproducibly.

In addition, the superconductor being a composite oxide is naturally poor in both malleability and ductility, and is hard to use as a superconducting electric cable or wire.

When the quenching phenomenon occurs, serious consequences are met such as the burning of the superconducting cable and the explosive vaporization of coolant, both due to the Joule heat.

The metal wire low in electric resistivity must, however, be formed of a metal such as silver (Ag) that is expensive and must therefore make the superconducting cable costly.

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