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: Mg 1 Be 2 , has a hexagonal AlB 2 type crystallographic structure and has a superconducting transition temperature (T c ) of 35 K. An alloy containing this intermetallic compound excels in malleability and ductility and constitutes the alloy superconductor having a superconducting transition temperature (T c ) 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.

1 . A method of making an alloy superconductor, characterized in that it comprises the steps of: mixing a Mg containing feedstock powder, a Be containing feedstock powder and a B containing feedstock powder together to form a mixture powder thereof so that the mixture powder contains Mg, Be and B at a compositional ratio of Mg:Be:B=1:x:y where 0<x<20 and 0<y<20, shaping said mixture powder into the form of a pellet, and heating said pellet in a pressurized inert gas to form the alloy superconductor. 
   
   
       2 . A method of making an alloy superconductor, characterized in that it comprises the steps of: mixing a Mg containing feedstock powder, a Be containing feedstock powder and a B containing feedstock powder together to form a mixture powder thereof so that the mixture powder contains Mg, Be and B at a compositional ratio of Mg:Be:B=1:x:y where 0<x<20 and 0<y<20, shaping said mixture powder into the form of pellet, and pressing and heating said pellet to form the alloy superconductor. 
   
   
       3 . A method of making an alloy superconductor as set forth in  claim 1 , characterized in that said pellet is heated in said inert gas under a pressure of 1 to 200 MPa at a temperature of 600 to 1100° C. for a period of several minutes or more. 
   
   
       4 . A method of making an alloy superconductor as set forth in  claim 2 , characterized in that said pellet is pressed and heated under a pressure of 0.1 to 6 GPa at a temperature of 700 to 1400° C. for a period of several minutes or more.