Superconducting articles of manufacture and method of producing same

Claim 2

A process for forming a bulk coating of Nb 3 Ge bonded to a copper substrate which comprises (a) uniformly entraining NbCl 5 powder in an argon gas stream, (b) forming a stream of argon gas and GeCl 4 vapor, (c) mixing said streams together and with hydrogen in a molar ratio which on the coreduction of said NbCl 5 and GeCl 4 by said hydrogen produces Nb 3 Ge, (d) heating the resulting gas mixture containing said entrained NbCl 5 powder to a temperature of 400° to 600° C., (e) flowing the resulting heated gas-vapor mixture over said copper substrate, and (f) heating said copper substrate and said gas-vapor mixture to a temperature greater than 650° C. to chemically vapor deposit Nb 3 Ge on said copper substrate.

Claim 3

The process of claim 1 wherein, prior to said chemical vapor deposition, hydrogen is flowed over said copper substrate for a time and at a temperature sufficient to reduce surface oxides on said substrate.

Claim 4

The process of claim 2 wherein said NbCl 5 powder is screened to -100 mesh or less and is vaporized at a temperature of about 500° C.

Claim 5

The process of claim 1 wherein the Nb:Ge molar ratio in said mixture of NbCl 5 vapor, GeCl 4 vapor, hydrogen, and argon is in the range of 2.3-3.0:1 and said chemical vapor deposition occurs at a temperature in the range of about 890° to 900° C.

Claim 6

An article of manufacture which comprises Nb 3 Ge bonded to a copper substrate made in accordance with the process of claim 1.

Claim 7

The article of manufacture of claim 5 wherein said Nb 3 Ge has the A-15 structure and a transition temperature in excess of 20° K.

Claim 8

The article of manufacture of claim 6 wherein said Nb 3 Ge is diffusion bonded to said copper.

Claim 9

In a process for the chemical vapor deposition of Nb 3 Ge on a metallic substrate by the coreduction of NbCl 5 vapor and GeCl 4 vapor by hydrogen at a temperature greater than 650° C., the improvement comprising (a) uniformly entraining NbCl 5 powder in an inert gas stream, and (b) completely vaporizing the resulting entrained NbCl 5 powder uniformly at a temperature between 400° and 600° C.; mixing hydrogen gas and GeCl 4 vapor with said NbCl 5 powder entrained in said inert gas and heating the resulting gas mixture to a temperature of 400° to 600° C. to vaporize said NbCl 5 powder; flowing said heating gas mixture over a copper substrate and heating said substate and said gas mixture to a temperature greater than 650° C.

Claim 10

In a process for the chemical vapor deposition of Nb 3 Ge on a metallic substrate by the coreduction of NbCl 5 vapor and GeCl 4 vapor by hydrogen at a temperature greater than 650° C., the improvement comprising (a) uniformly entraining NbCl 5 powder in an inert gas stream, and (b) completely vaporizing the resulting entrained NbCl 5 powder uniformly at a temperature between 400° and 600° C.; mixing hydrogen gas and GeCl 4 vapor with said NbCl 5 powder entrained in said inert gas and heating the resulting gas mixture to a temperature of 400° to 600° C. to vaporize said NbCl 5 powder; flowing said heating gas mixture over a copper substrate and heating said substate and said gas mixture to a temperature greater than 650° C.