Superconducting thin film

Claim 2

In a superconducting thin film composed of compound oxide containing at least one of element selected from a group comprising Y, La, Gd, Ho, Er, Tm, Yb, Nd, Sm, Eu and Lu, Ba and Cu, improvement in that said thin film consists of a single crystal or polycrystal whose c-axis is orientated to a predetermined direction.

Claim 3

Improvement in set forth in Claim 1, characterized in that said thin film is a thin film prepared by physical vapor deposition technique on a substrate consisting of a single crystal.

Claim 4

Improvement in set forth in Claim 2, characterized in that said substrate of single crystal has such lattice constant or lattice constants in a-­axis and/or b-axis that are proximate to those of a crystal represented by a formula: Ln₁Ba₂Cu₃O₇ in which, Ln stands for an element selected from a group comprising Y, La, Gd, Ho, Er, Tm, Yb, Nd, Sm, Eu and Lu.

Claim 5

Improvement in set forth in Claim 2 or 3, characterized in that a surface of said substrate of single crystal on which said thin film is deposited is a crystal face of (100) plane.

Claim 6

Improvement in set forth in Claim 2 or 3, characterized in that a surface of said single crystal substrate on which said thin film is deposited is a crystal face of (110) plane.

Claim 7

Improvement in set forth in any one of Claim 2 to 5, characterized in that said substrate of single crystal is a single crystal selected from a group comprising MgO, SrTiO₃, Al₂O₃, sapphire, SiO₂, quartz, YSZ and ZnO.

Claim 8

Improvement in set forth in any one of Claim 1 to 5, characterized in that X-ray diffraction chart of said film possesses at least one crystal face of (00n) plane having an intensity J 00n in a X-ray diffraction pattern which satisfies the following relation: J 00n /J MAX ≧ 2 (I 00n /I MAX ) in which (oon) is an index of a crystal face of said thin film, wherein "n" is an integer I MAX is an intensity of the most intense peak in a powder X-ray diffraction chart measured in a powder sample of a compound oxide represented by a formula: Y₁Ba₂Cu₃O₇ used as a reference, I 00n is an intensity of the (00n) plane in said powder X-ray diffraction chart, J MAX is an intensity of a crystal face which has the same index as the crystal face having the most intense peak in said powder X-ray diffraction chart and is observed in a X-ray diffraction chart measured in said thin film, J 00n is an intensity of the (00n) plane in said X-ray diffraction chart measured in said thin film.

Claim 9

Improvement in set forth in Claim 7, characterized in that said (00n) planes of said thin film are (002) plane, (003) plane, (005) plane and (006) plane.

Claim 10

Improvement in set forth in any one of Claim 1 to 8, characterized in that each intensity of (002) plane, (003) plane, (005) plane and (006) plane observed in a X-ray diffraction chart measured in said thin film is more than double of intensities of (111) plane and (112) plane.

Claim 11

Improvement in set forth in any one of Claim 1 to 9, characterized in that said thin film is composed of a compound oxide containing Ba, Y and Cu and exhibits a X-ray diffraction pattern shown in Fig. 1.

Claim 14

A method in set forth in Claim 11, characterized in that a surface of said substrate of single crystal on which said thin film is deposited is a crystal face of (100) plane.

Claim 15

A method in set forth in Claim 11, characterized in that a surface of said single crystal substrate on which said thin film is deposited is a crystal face of (110) plane.

Claim 16

A method in set forth in any one of Claim 11 to 13, characterized in that said substrate of single crystal is a single crystal selected from a group comprising MgO, SrTiO₃, Al₂O₃, sapphire, SiO₂, quartz, YSZ and ZnO.

Claim 17

A method in set forth in any one of Claim 11 to 14, characterized in that X-ray diffraction chart of said thin film possesses at least one crystal face of (00n) plane having an intensity J 00n in a X-ray diffraction pattern which satisfies the following relation: J 00n /J MAX ≧ 2 (I 00n /I MAX ) in which (oon) is an index of a crystal face of said thin film, wherein "n" is an integer I MAX is an intensity of the most intense peak in a powder X-ray diffraction chart measured in a powder sample of a compound oxide represented by a formula: Y₁Ba₂Cu₃O₇ used as a reference, I 00n is an intensity of the (00n) plane in said powder X-ray diffraction chart, J max is an intensity of a crystal face which has the same index as the crystal face having the most intense peak in said powder X-ray diffraction chart and is observed in a X-ray diffraction chart measured in said thin film, J 00n is an intensity of the (00n) plane in said X-ray diffraction chart measured in said thin film.

Claim 18

A method in set forth in Claim 15, characterized in that said (00n) planes of said thin film are (002) plane, (003) plane (005) plane and (006) plane.

Claim 19

A method in set forth in any one of Claim 11 to 16, characterized in that each intensity of (002) plane, (003) plane, (005) plane and (006) plane observed in a X-ray diffraction chart measured in said thin film is more than double of intensities of (111) plane and (112) plane.

Claim 20

A method in set forth in any one of Claim 11 to 17, characterized in that said thin film is composed of a compound oxide containing Ba, Y and Cu and exhibits a X-ray diffraction pattern shown in Fig. 1.