Process for the production of high temperature superconductor wires

Patent metadata

Field	Value
Publication number	US-10840429-B2
Application number	US-201615560826-A
Country	US
Kind code	B2
Filing date	Mar 16, 2016
Priority date	Mar 26, 2015
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

The present invention is in the field of processes for the production of high temperature super-conductor wires. In particular, the present invention relates to a process for the production of high temperature superconductor wires comprising heating a film comprising yttrium or a rare earth metal, an alkaline earth metal, and a transition metal to a temperature of at least 700° C. and cooling the film to a temperature below 300° C., wherein the heating and cooling is per-formed at least twice.

First claim

The invention claimed is:

1. A process for producing high temperature superconductor wires, the process comprising
heating a film comprising yttrium or a rare earth metal, an alkaline earth metal, and a transition metal to a temperature of at least 700° C. and cooling the film to a temperature below 300° C.,
wherein the heating and cooling is performed at least twice and a partial pressure of water during a first heating to a temperature of at least 700° C., denoted P 1,w , a total pressure during the first heating to the temperature of at least 700° C., denoted P 1 , a partial pressure of water during a second heating to a temperature of at least 700° C., denoted P 2,w , and a total pressure during the second heating to the temperature of at least 700° C., denoted P 2 , fulfill the relationship:

P

1
,
W

P
1

<

P

2
,
W

P
2

when P 1,w , P 1 , P 2,w and P 2 are expressed in mbar.

2. The process according to claim 1 , wherein the heating comprises developing seed crystals of the high temperature superconductor in the film during the first heating to the temperature of at least 700° C., thereby constituting at least 70% of the film different phases.

3. The process according to claim 1 , wherein:
the first heating to the temperature of at least 700° C. includes at least one temperature plateau and the second heating to the temperature of at least 700° C. includes at least one temperature plateau;
the temperature plateau is a period of time in which a temperature changes at a rate of less than 1000° C./h, and
a time-average temperature of a longest temperature plateau during the first heating to the temperature of at least 700° C., denoted T 1 , is lower than a time-average temperature of a longest temperature plateau during the second heating to the temperature of at least 700° C., denoted T H .

4. The process according to claim 1 , wherein:
the first heating to the temperature of at least 700° C. includes at least two temperature plateaus with temperatures of at least 700° C.;
each of the temperature plateaus is a period of time in which a temperature changes at a rate of less than 1000° C./h, and
a temperature of a first temperature plateau, denoted T 1,1 , is higher than a temperature of a second temperature plateau, denoted T 1,2 .

5. The process according to claim 1 , wherein the film is passed through a furnace at a speed of 1 to 300 m/h.

6. The process according to claim 1 , wherein the film is consecutively passed through different furnaces.

7. The process according to claim 1 , wherein the film comprises yttrium, barium and copper.

8. The process according to claim 1 , wherein a molar ratio of the transition metal and the yttrium or rare earth metal in the film is 3:1.0 to 3:1.5.

9. The process according to claim 1 , wherein a molar ratio of the transition metal and the earth alkaline metal in the film is 3:1.5 to 3:2.0.

10. The process according to claim 1 , wherein the film is on a substrate comprising Ni and 1-10 at-% tungsten.

11. The process according to claim 10 , wherein between the substrate and the film there is a buffer layer comprising lanthanum zirconate, cerium oxide, or both.

Assignees

• Basf Se

Inventors

• Feenstra Ron
• Sadewasser Mario
• Baecker Michael

Classifications

• H10N60/0548

  by deposition and subsequent treatment, e.g. oxidation of pre-deposited material · CPC title

• H10N60/0324 Primary

  from a solution · CPC title

• H01B13/0016

  for heat treatment · CPC title

• H01B12/00

  Superconductive or hyperconductive conductors, cables, or transmission lines · CPC title

• H01L39/2425 Primary

  Electricity · mapped topic