Superconducting wire material, superconducting coil, superconducting magnet, superconducting motor, superconducting generator, superconducting aircraft, and superconducting device

A superconducting wire comprising:

• a substrate;
• a first region provided on the substrate, the first region containing barium (Ba), copper (Cu), oxygen (O), and at least one first rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and the first region extending in a first direction along a surface of the substrate;
• a second region provided on the substrate, the second region containing barium (Ba), copper (Cu), oxygen (O), and at least one second rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and the second region extending in the first direction;
• and
• a third region provided on the substrate, the third region provided between the first region and the second region, the third region being in contact with the first region and the second region, the third region containing praseodymium (Pr), barium (Ba), copper (Cu), oxygen (O), and at least one third rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and the third region extending in the first direction, wherein
• a surface density of particles having an aspect ratio of 3 or more present on a surface of the third region is larger than a surface density of particles having an aspect ratio of 3 or more present on a surface of the first region, and
• the surface density of the particles having an aspect ratio of 3 or more present on the surface of the third region is larger than a surface density of particles having an aspect ratio of 3 or more present on a surface of the second region.