Nanoparticles for the use as pinning centers in superconductors

• US 10,450,199 B2
• Filed: 02/24/2016
• Issued: 10/22/2019
• Est. Priority Date: 03/02/2015
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Hemgesberg, Maximilian, Schwall, Denis, Staudt, Thorsten Martin, Driessche, Isabel van, De Keukeleere, Katrien, De Roo, Jonathan, Gruendling, Till, Maier, Matthias, Baecker, Michael, Bennewitz, Jan, Feenstra, Ron, Rijckaert, Hannes, Zeger, Hens
• Primary Examiner(s): Rump, Richard M
• Application Number:
  US15/554,742
• Publication Number:
  US 20180044197A1
• Time in Patent Office: 1,336 Days
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 23/047 Titanium dioxide
• CPC Class Codes: C01G 25/02 Oxides
• CPC Class Codes: C01G 27/02 Oxides
• CPC Class Codes: C01G 35/00 Compounds of tantalum
• CPC Class Codes: C01P 2002/60 Compounds characterised by their crystallite size
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/74 by peak-intensities or a ratio thereof only
• CPC Class Codes: C01P 2004/52 highly monodisperse size distribution
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C09C 1/00 Treatment of specific inorganic materials other than fibrous fillers tenebrescent materials C09K9/00; luminescent materials C09K11/00; Preparation of carbon black
• CPC Class Codes: C09C 1/3669 Treatment with low-molecular organic compounds
• CPC Class Codes: C09C 3/08 Treatment with low-molecular-weight non-polymer organic compounds C09C3/006, C09C3/048 take precedence
• CPC Class Codes: C09D 11/033 characterised by the solvent
• CPC Class Codes: C09D 11/38 characterised by non-macromolecular additives other than solvents, pigments or dyes
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: H10N 60/0324 from a solution
• CPC Class Codes: H10N 60/0828 Introducing flux pinning centres

Abstract

The present invention is in the field of nanoparticles, their preparation and their use as pinning centers in superconductors. In particular the present invention relates to nanoparticles comprising an oxide of Sr, Ba, Y, La, Ti, Zr, Hf, Nb, or Ta, wherein the nanoparticles have a weight average diameter of 1 to 30 nm and wherein an organic compound of general formula (I), (II) or (III) or an organic compound containing at least two carboxylic acid groups on the surface of the nanoparticles (I) (II) (III) wherein a is 0 to 5, b and c are independent of each other 1 to 14, n is 1 to 5, f is 0 to 5, p and q are independent of each other 1 to 14, and e and f are independent of each other 0 to 12.

Claims

1. Nanoparticles, comprising:

an oxide of at least one element selected from the group consisting of Sr, Ba, Y, La, Ti, Zr, Hf, Nb, and Ta,

wherein;

the nanoparticles have a weight average diameter of 1 to 30 nm; and

an organic compound of general formula (I), (II) or (III) is on the surface of the nanoparticles;

2. The nanoparticles according to claim 1, wherein the nanoparticles comprise ZrO₂, HfO₂ or Ta₂O₅.

3. The nanoparticles according to claim 1, wherein a trialkyl phosphorous oxide or a fatty acid is additionally on the surface of the nanoparticles.

4. The nanoparticles according to claim 1, wherein the nanoparticles are crystalline.

5. The nanoparticles according to claim 1, wherein the nanoparticles have a dispersity of particle size distribution D₉₀/D₅₀ measured by dynamic light scattering of 1.2 or less.

6. A process for producing the nanoparticles of claim 1, the process comprising:

(i) precipitating nanoparticles comprising the oxide of at least one element selected from the group consisting of Sr, Ba, Y, La, Ti, Zr, Hf, Nb, and Ta from a suspension comprising a non-polar solvent, wherein the nanoparticles have a weight average diameter of 1 to 30 nm; and

(ii) adding an alcohol and the organic compound of general formula (I), (II) or (III) to the precipitated nanoparticles, to obtain the nanoparticles.

7. The process according to claim 6, wherein the suspension comprising a non-polar solvent and nanoparticles is produced by a condensation or esterification reaction comprising a soluble precursor in the presence of a surfactant.

8. An ink for the preparation of a high temperature superconductor, the ink comprising:

(a) an yttrium or rare earth metal-containing compound;

(b) an alkaline earth metal-containing compound;

(c) a transition metal-containing compound;

(d) an alcohol; and

(e) the nanoparticles of claim 1.

9. The ink according to claim 8, wherein the alcohol is a mixture of methanol and C₂ to C₁₂, alcohols.

10. The ink according to claim 8, wherein at least one of the rare earth metal-containing compound or the yttrium-containing compound, the alkaline earth metal-containing compound and the transition metal-containing compound contains fluorine.

11. The ink according to claim 8, comprising the nanoparticles at a concentration at which a molar ratio of metal in the nanoparticles to the yttrium-containing compound or the rare earth metal-containing compound is 1 to 30 %.

12. A superconductor, comprising the nanoparticles of claim 1 as pinning centers in the superconductors.