Connection structure of superconducting layer, superconducting wire, superconducting coil, superconducting devce, and connection method of superconducting layer

A connection structure of a superconducting layer comprising:

• a first superconducting layer;
• a second superconducting layer;
• and
• a connection layer provided between the first superconducting layer and the second superconducting layer, and the connection layer including a first substance containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O) and a second substance containing at least one metal element selected from the group consisting of silver (Ag), aluminum (Al), indium (In), copper (Cu), tin (Sn), and zinc (Zn),
• wherein the second substance is in contact with the first superconducting layer and the second superconducting layer, and
• the second substance is continuous between the first superconducting layer and the second superconducting layer.

A superconducting wire comprising:

• a first superconducting wire including a first superconducting layer;
• a second superconducting wire including a second superconducting layer;
• a third superconducting layer having a first surface and a second surface facing the first surface;
• and
• a connection layer provided between the first superconducting layer and the third superconducting layer and between the second superconducting layer and the third superconducting layer, and the connection layer including a first substance containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O) and a second substance containing at least one metal element selected from the group consisting of silver (Ag), aluminum (Al), indium (In), copper (Cu), tin (Sn), and zinc (Zn),
• wherein the first superconducting layer and the second superconducting layer are located on a side of the first surface of the third superconducting layer,
• a first area ratio at a first interface between the first superconducting layer and the connection layer is 1% or more and 50% or less, the first area ratio is an area ratio of a first region per unit area, the first region is a region where the second substance and the first superconducting layer are in contact with each other, and
• a second area ratio at a second interface between the second superconducting layer and the connection layer is 1% or more and 50% or less, the second area ratio is an area ratio of a second region per unit area, the second region is a region where the second substance and the second superconducting layer are in contact with each other, and
• a third area ratio at a third interface between the third superconducting layer and the connection layer is 1% or more and 50% or less, the third area ratio is an area ratio of a third region per unit area, the third region is a region where the second substance and the third superconducting layer are in contact with each other.

A superconducting wire comprising:

• a first superconducting wire including a first superconducting layer;
• a second superconducting wire including a second superconducting layer;
• a third superconducting layer having a first surface and a second surface facing the first surface;
• and
• a connection layer provided between the first superconducting layer and the third superconducting layer and between the second superconducting layer and the third superconducting layer, and the connection layer including a first substance containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O) and a second substance containing at least one metal element selected from the group consisting of silver (Ag), aluminum (Al), indium (In), copper (Cu), tin (Sn), and zinc (Zn),
• wherein the first superconducting layer and the second superconducting layer are located on a side of the first surface of the third superconducting layer,
• a portion of the second substance is in contact with the first superconducting layer and the third superconducting layer,
• the portion of the second substance is continuous between the first superconducting layer and the third superconducting layer,
• a different portion of the second substance is in contact with the second superconducting layer and the third superconducting layer, and
• the different portion of the second substance is continuous between the second superconducting layer and the third superconducting layer.

A connection method of a superconducting layer, comprising:

• preparing a first superconducting layer and a second superconducting layer;
• sandwiching a substance containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O), and silver oxide between the first superconducting layer and the second superconducting layer;
• and
• performing a heat treatment in a state where the first superconducting layer and the second superconducting layer are pressurized.