Method for making YBCO superconductor

Patent metadata

Field	Value
Publication number	US-11767267-B2
Application number	US-202318115112-A
Country	US
Kind code	B2
Filing date	Feb 28, 2023
Priority date	Sep 24, 2018
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A method of producing polycrystalline Y 3 Ba 5 Cu 8 O y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950° C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000° C. for up to 72 hours. The polycrystalline Y 3 Ba 5 Cu 8 O y thus produced is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and embedded with spherical nanoparticles of yttrium deficient Y 3 Ba 5 Cu 8 O y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y 3 Ba 5 Cu 8 O y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.

First claim

The invention claimed is:

1. A method for making a YBCO superconductor having two superconducting transitions, comprising:
mixing powders of yttrium (III) oxide, barium carbonate, and copper(II) oxide then pelletizing to form a pelletized mixture;
calcining the pelletized mixture at a first temperature in the range 850-900° C. to form a first calcined mixture;
grinding the first calcined mixture to form a first intermediate calcined mixture, then
calcining the first intermediate calcined mixture at a temperature in the range 850-900° C. to form a second calcined mixture, wherein the second calcined mixture is free from carbonate;
ball milling the second calcined mixture at a ball to powder ratio of 5:2 to produce a ball milled sample; and
sintering the ball milled sample at a second temperature in the range 900-1000° C. to form a polycrystalline Y 3 Ba 5 Cu 8 O y material,
wherein the polycrystalline Y 3 Ba 5 Cu 8 O y material is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and are embedded with spherical nanoparticles of yttrium deficient Y 3 Ba 5 Cu 8 O y having an average diameter of 5 to 20 nm, wherein the spherical nanoparticles are in the form of flower-like agglomerates having an average particle size of 30 to 60 nm.

2. The method of claim 1 , wherein the pelletizing includes uniaxially pressing a mixture of the yttrium (III) oxide, the barium carbonate salt, and the copper(II) oxide under an applied pressure of about 100 MPa.

3. The method of claim 1 , wherein the second calcined mixture is ball milled using a planetary ball milling technique.

4. The method of claim 1 , wherein the second calcined mixture is ball milled with stainless-steel balls and vials.

5. The method of claim 1 , wherein the second calcined mixture is ball milled at a rotational speed of 300 to 600 rpm.

6. The method of claim 1 , wherein the second calcined mixture is ball milled for 3 to 5 hours.

7. The method of claim 1 , wherein the second calcined mixture is ball milled noncontinuously in increments of 20 to 30 minutes separated by cooling off periods of 5 to 10 min.

8. The method of claim 1 , wherein the ball milled sample is pelletized under a uniaxial pressure of about 750 MPa.

9. The method of claim 1 , wherein the ball milled sample is sintered in an oxygen atmosphere at 950° C. for up to 72 hours.

10. The method of claim 1 , wherein the polycrystalline Y 3 Ba 5 Cu 8 O y material has a normalized transport critical current density, JctN, of 0.040 to 0.042 under an applied transverse magnetic field (μ 0 H) of 100 mT.

11. The method of claim 1 , wherein the polycrystalline Y 3 Ba 5 Cu 8 O y material has a magnetization critical current density J cm of 13×10 3 to 15×10 3 A·cm −2 and 550 to 570 A·cm −2 at 0 Tesla and 1 Tesla, respectively.

12. The method of claim 1 , wherein the polycrystalline Y 3 Ba 5 Cu 8 O y material has a lower critical magnetic field (B c1 (0)) of 7 to 7.25 Tesla and an upper critical magnetic field (B c2 (0)) of 580 to 585 Tesla.

13. The method of claim 1 , wherein the polycrystalline Y 3 Ba 5 Cu 8 O y material has an estimated critical current density at temperature T=0K J c (0)) of 320×10 3 to 330×10 3 A·cm −2 .

Assignees

• Univ Imam Abdulrahman Bin Faisal
• Imam Abdulrahman Bin Faisal Univesity

Inventors

• Slimani Yassine

Classifications

• C04B35/4504 Primary

  containing rare earth oxides · CPC title

• C04B35/6262

  of calcined, sintered clinker or ceramics · CPC title

• C04B35/62615

  High energy or reactive ball milling · CPC title

• C30B29/225

  based on rare earth copper oxides, e.g. high T-superconductors · CPC title

• H10N60/857

  comprising copper oxide · CPC title