Rare earth-type tape-shaped oxide superconductor and a composite substrate used for the same

A composite substrate for a rare earth-type tape-shaped oxide superconductor, comprising:

• a metal substrate which is formed of non-oriented and non-magnetic metal;
• and
• a first metal layer and a second metal layer which are respectively bonded to opposing surfaces of said metal substrate through a first bonding layer and a second bonding layer, respectively;
• and
• wherein the first and second bonding layers are formed by surface activated bonding at normal temperature, followed by a heat-treatment or hot rolling,
• wherein the first and second bonding layers are formed by surface activated bonding at normal temperature, followed by a heat-treatment or hot rolling,
• wherein said first metal layer comprises plural layers mutually bonded by surface activated bonding, followed by a heat-treatment or hot rolling,
• wherein said first metal layer has first and second opposing surfaces,
• wherein at least said first surface of said first metal layer has a biaxially-oriented cubic texture,
• wherein said second surface of said first metal layer is bonded to said metal substrate through said second bonding layer, and
• wherein said metal substrate has a larger mechanical strength than that of said first and second metal layers.

A composite substrate for a rare earth-type tape-shaped oxide superconductor, comprising:

• a metal substrate which is formed of non-oriented and non-magnetic metal;
• and
• a first metal layer and a second metal layer which are respectively bonded to opposing surfaces of said metal substrate through a first bonding layer and a second bonding layer, respectively, and which function to prevent deformation of the composite substrate;
• and
• wherein the first and second bonding layers are formed by surface activated bonding at normal temperature, followed by a heat-treatment or hot rolling,
• wherein said first metal layer is formed of plural layers and functions to prevent diffusion of an element from said metal substrate,
• wherein said plural layers of said metal layer are mutually bonded surface activated bonding, followed by a heat-treatment or hot rolling,
• wherein said first metal layer has first and second opposing surfaces,
• wherein at least said first surface of said first metal layer has a biaxially-oriented cubic texture,
• wherein said second surface of said first metal layer is bonded to said metal substrate through said second bonding layer, and
• wherein said metal substrate has a larger mechanical strength than that of said first and second metal layers.