Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wires

Abstract

A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

1 . A method for producing doped boron, the steps consisting of: introducing a boron : containing vapor into a reaction vessel; introducing a dopant vapor into the reaction vessel to provide a mixture of the dopant vapor and the boron-containing vapor; and, heating the mixture to produce doped boron. 
     
     
         2 . The method of  claim 1  wherein the boron-containing vapor is a hydrogen and boron trichloride mixture. 
     
     
         3 . The method of  claim 1  wherein the dopant vapor is titanium tetrachloride vapor. 
     
     
         4 . The method of  claim 3  wherein the boron-containing vapor is a hydrogen and boron trichloride mixture. 
     
     
         5 . The method of  claim 4  wherein the hydrogen and boron trichloride mixture is a roughly stoichiometric mixture. 
     
     
         6 .- 20 . (canceled) 
     
     
         21 . The method of  claim 1  wherein the dopant vapor is a hydrogen and titanium tetrachloride mixture. 
     
     
         22 . A method for producing doped boron, the steps consisting of:
 (a) introducing a boron-containing vapor into a reaction vessel by metering a flow of hydrogen and metering a flow of boron trichloride vapor through the reaction vessel;   (b) introducing a dopant vapor into the reaction vessel by passing at least a portion of the flow of hydrogen through a bubbler containing liquid titanium tetrachloride;   mixing the hydrogen/titanium tetrachloride mixture emerging from the bubbler with the flow of boron trichloride going to the reaction vessel to form a boron-containing vapor/dopant-containing vapor mixture; and passing the boron-containing vapor/dopant-containing vapor mixture through the reaction vessel; and,   (c) heating the boron-containing vapor/dopant-containing vapor mixture in the reaction vessel to produce doped boron.   
     
     
         23 . The method according to  claim 22  wherein a metered flow of hydrogen at about 3.1 liters per minute and a metered flow of boron trichloride at about 4.2 liters per minute are flowed through the reaction vessel. 
     
     
         24 . The method according to  claim 22  wherein step (c) comprises the step of providing a heated surface inside the reaction vessel to heat the boron-containing vapor/dopant-containing vapor mixture. 
     
     
         25 . The method according to  claim 22  wherein step (c) comprises the steps of heating a silicon carbide fiber by electrical resistance heating to a temperature of about 1100-1300 degrees Celsius and passing said heated fiber through the reaction vessel in contact with the boron-containing vapor/dopant-containing vapor mixture.