Superconducting member
AssigneeKabushiki Kaisha Toshiba
InventorsKohei Nakayama, Mutsuki Yamazaki
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Abstract
This invention provides a thin superconducting oxide film, which can realize a high critical current, and a superconducting member having a high level of electric power resistance. The superconducting member comprises a sapphire R face substrate, a buffer layer formed of grain lumps of an oxide provided on the sapphire R face substrate, and a superconducting layer provided on the buffer layer. The nearest neighbor distance between oxygen atoms in the oxide and the grain diameter of grain lumps of the oxide have been specified. The superconducting member can be used as a member for superconducting filters.
Claims15
A superconducting member comprising:
- a sapphire R face substrate;
- a buffer layer provided on at least one surface of the sapphire R face substrate;
- and
- a superconducting layer having a thickness of not less than 350 nm and not more than 1000 nm provided on the buffer layer,
- wherein the buffer layer is formed of grain lumps of an oxide, the nearest neighbor distance between the oxygen atoms constituting a crystal face of the oxide parallel to the substrate surface is not more than 0.2705 nm, not less than 90% of grain lumps have a grain diameter of not less than 20 nm and not more than 70 nm, not less than 90% of the grain lumps satisfy a requirement of 5 nm ≦D−d ≦20 nm wherein D represents a maximum thickness of the grain lump, and d represents a thickness of the grain lump in its part adjacent to other grain lump.
A process for producing a superconducting member, comprising:
- providing a sapphire R face substrate;
- forming a buffer layer of grain lumps of an oxide on at least one surface of the substrate;
- and
- forming a superconducting layer having a thickness of not less than 350 nm and not more than 1000 nm on the buffer layer,
- wherein the oxide is controlled so that the nearest neighbor distance between oxygen atoms constituting a crystal face of the oxide parallel to the substrate surface is not more than 0.2705 nm, not less than 90% of grain lumps have a grain diameter of not less than 20 nm and not more than 70 nm, not less than 90% of the grain lumps satisfy a requirement of 5 nm≦D−d 20 nm wherein D represents a maximum thickness of the grain lump, and d represents a thickness of the grain lump in its part adjacent to other grain lump.
Dependencies are inferred from the claim text.