Oxide superconducting wire and method of manufacturing the same
An oxide superconducting wire includes a superconducting layer deposited on a substrate. The superconducting layer includes an oxide superconductor RE-Ba—Cu—O and artificial pinning centers ABO 3 , where RE is a rare earth element, A is Ba, Sr or Ca, and B is Hf, Zr, or Sn. In a TEM image of a cross-section of the superconducting layer, a standard deviation σ of an inclination angle of the artificial pinning center rods with respect to a cross-sectional direction of the superconducting layer is 6.13° to 11.73° and an average length of the artificial pinning center rods is 19.84 to 25.44 nm.
1. An oxide superconducting wire comprising:
a superconducting layer deposited on a substrate, wherein
the superconducting layer comprises:
an oxide superconductor comprising RE-Ba—Cu—O; and
artificial pinning center rods comprising ABO 3 , where
RE is a rare earth element,
A is Ba, Sr or Ca, and
B is Hf, Zr, or Sn, and
in a TEM image of a cross-section of the superconducting layer, a standard deviation n of an inclination angle of the artificial pinning center rods with respect to a cross-sectional direction of the superconducting layer is 6.13° to 11.73° and an average length of the artificial pinning center rods is 19.84 to 25.44 nm.
2. The oxide superconducting wire according to claim 1 , wherein a number density of the artificial pinning center rods in a plane perpendicular to the cross-sectional direction of the superconducting layer is 1000 to 3500 pieces/μm 2 .
3. The oxide superconducting wire according to claim 1 , wherein a ratio of a-axis oriented grains of the oxide superconductor calculated by an X-ray intensity ratio is 10% or less.
4. The oxide superconducting wire according to claim 1 , wherein a critical current density Jc at a temperature of 30K and a magnetic field of 2 T is 6.0 MA/cm 2 or more.
5. A method of manufacturing an oxide superconducting wire having a critical current density Jc of 6.0 MA/cm 2 or more in a magnetic field of 2 T in a c-axis direction at a temperature of 30K, the method comprising:
depositing, by a pulsed laser deposition method at a deposition rate of 23 nm/sec or more, a superconducting layer that comprises:
an oxide superconductor comprising RE-Ba—Cu—O; and
artificial pinning center rods comprising ABO 3 , where
RE is a rare earth element,
A is Ba, Sr or Ca, and
B is Hf, Zr or Sn.
6. The method of manufacturing an oxide superconducting wire according to claim 5 , wherein the deposition rate of the superconducting layer is 36 nm/sec or more.
7. The method of manufacturing an oxide superconducting wire according to claim 6 , wherein the deposition rate of the superconducting layer is 36 to 70 nm/sec.
8. The method of manufacturing an oxide superconducting wire according to claim 7 , wherein the deposition rate of the superconducting layer is 46 to 70 nm/sec.
9. The method of manufacturing an oxide superconducting wire according to claim 5 , wherein a number density of the artificial pinning center rods in a plane perpendicular to the cross-sectional direction of the superconducting layer is 1000 to 3500 pieces/μm 2 .