Oxide Superconductor Structure for Lower AC Loss and Higher Strength

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Solution Overview

Problem

Current methods for manufacturing oxide superconducting wires, such as the laser scribing technology, face challenges including high AC loss, mechanical weakness, and issues related to peeling and debris formation, which hinder their application in high-power and high-field applications.

Innovation Solution

The development of an oxide superconductor with a specific layer structure comprising superconducting regions and non-superconducting regions, where the non-superconducting regions are doped with praseodymium (Pr) to create a continuous perovskite structure, thereby enhancing mechanical strength and reducing AC loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the superconducting wire is divided into thin wires to reduce AC loss, then AC loss decreases, but mechanical strength deteriorates

Engineering Contradiction:
ImproveAC lossVSAvoidmechanical strength
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The superconducting layer is divided into multiple thin superconducting regions (e.g., 8 regions of 0.5mm width from 4mm wire), which reduces AC loss by approximately 1/8. This segmentation allows the wire to handle AC currents more efficiently while maintaining the overall structural integrity through the non-superconducting regions that provide mechanical support.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wire structure combines superconducting regions with non-superconducting regions to form a composite material system. The non-superconducting regions (such as matrix materials or protective layers) provide mechanical strength and structural stability, while the superconducting regions carry the current with minimal energy loss. This composite approach resolves the contradiction between thinning for AC loss reduction and maintaining mechanical strength.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If laser scribing technology is used to pattern the superconducting layer, then AC loss is reduced, but peeling and debris formation occur

Engineering Contradiction:
ImproveAC lossVSAvoidpeeling and debris formation
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

A buffer layer or intermediate layer is introduced between the superconducting layer and the substrate. This intermediary layer prevents direct adhesion issues that cause peeling during laser scribing, while also capturing debris and preventing it from compromising the superconducting properties. The buffer layer acts as a mediator that protects the superconducting layer from damage during the patterning process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer layer is deposited beforehand to cushion and protect the superconducting layer during subsequent laser scribing operations. This pre-established protective layer prevents peeling and debris formation by absorbing the mechanical and thermal stresses generated during laser processing, ensuring the reliability of the final patterned structure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Loss of energy

If the superconducting layer is thinned to reduce AC loss, then energy efficiency improves, but mechanical weakness increases

Engineering Contradiction:
ImproveAC lossVSAvoidmechanical strength
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The superconducting layer is segmented into multiple thin regions separated by non-superconducting regions. Each thin superconducting region (e.g., 0.5mm wide segments) minimizes AC loss, while the separating non-superconducting regions provide mechanical reinforcement. This segmentation strategy allows the wire to achieve low AC loss without sacrificing overall mechanical strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wire is constructed as a composite structure with thin superconducting regions embedded in a mechanically robust non-superconducting matrix. The composite design allows the superconducting portions to be thin for energy efficiency while the matrix material provides the necessary mechanical strength and structural integrity.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces AC loss and improves the mechanical strength of the superconducting wire, addressing the limitations of existing technologies and enabling more efficient use in high-power applications.

Implementation Method 1

the non-superconducting region having a continuous perovskite structure that is continuous with the continuous perovskite structure of the at least one superconducting region

Methodology Applied
Scientific EffectPerovskite structure:

Implementation Method 2

Superconductivity is a phenomenon in which a resistance value becomes completely zero

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentEP3968396B1Oxide superconductor and method for manufacturing the same
Publication Date: 2025.01.29 KK TOSHIBA
  • EP3968396B1 patent drawingFigure 1
  • EP3968396B1 patent drawingFigure 2
  • EP3968396B1 patent drawingFigure 3

AI summary

The disclosed superconductor arrangement (100) comprises an oxide superconducting layer (30) including at least one superconducting region (31) containing barium, copper, and a rare earth element, having a continuous perovskite structure and having a size of 100 nm x 100 nm x 100 nm or more, and a non-superconducting region (32) in contact with the at least one superconducting region, containing praseodymium, barium, copper, and a rare earth element, having a ratio of a number of atoms of the praseodymium to a sum of a number of atoms of the rare earth element and the praseodymium being 20% or more, having a continuous perovskite structure continuous with the continuous perovskite structure of the superconducting region and having a size of 100 nm x 100 nm x 100 nm or more. Manufacturing by a sol-gel process using plural coating solutions is disclosed as well.