JPH0675100B2 - SQUID element - Google Patents
SQUID elementInfo
- Publication number
- JPH0675100B2 JPH0675100B2 JP1215204A JP21520489A JPH0675100B2 JP H0675100 B2 JPH0675100 B2 JP H0675100B2 JP 1215204 A JP1215204 A JP 1215204A JP 21520489 A JP21520489 A JP 21520489A JP H0675100 B2 JPH0675100 B2 JP H0675100B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- squid
- substrate
- superconducting thin
- temperature superconducting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- Measuring Magnetic Variables (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Description
【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は高温超電導薄膜を用いたSQUID素子に関する。DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a SQUID element using a high temperature superconducting thin film.
なお、本発明のSQUID素子は、例えば生体磁気計測の分
野、金属疲労や金属腐食等を検査する材料試験や資源探
査、あるいは地震予知等の、極めて微弱な磁気の検出分
野等に適用することができる。The SQUID element of the present invention can be applied to, for example, a field of biomagnetic measurement, a material test for inspecting metal fatigue, metal corrosion, and the like, resource exploration, or earthquake prediction, and a field of extremely weak magnetism. it can.
＜従来の技術＞ SQUID素子は一般に極めて感度が高いために、それに応
じた磁気雑音対策が必要となる。<Prior Art> Since SQUID elements are generally extremely sensitive, it is necessary to take measures against magnetic noise.
このような磁気雑音対策の一つとして、従来、高温超電
導体を円筒状等に焼結したたシールドケースがあり、SQ
UID素子をその内部に入れて磁気ないし電磁シールドし
ている。As one of the countermeasures against such magnetic noise, there is a shield case made by sintering a high-temperature superconductor into a cylindrical shape.
The UID element is placed inside to shield it magnetically or electromagnetically.
＜発明が解決しようとする課題＞ ところで、原料粉末を焼結して得られる高温超電導体
は、一般に臨界電流密度が低く、従ってシールド効果は
充分とは言いがたい。<Problems to be Solved by the Invention> By the way, a high-temperature superconductor obtained by sintering a raw material powder generally has a low critical current density, and therefore, it cannot be said that the shielding effect is sufficient.
本発明はこのような点に鑑みてなされたもので、特に別
途シールドケース等を用意することなく、磁気雑音に対
してより充分なシールド効果を持ち、安定に動作するこ
とのできるSQUID素子を提供することを目的としてい
る。The present invention has been made in view of the above points, and provides a SQUID element that has a more sufficient shield effect against magnetic noise and can operate stably without preparing a separate shield case or the like. The purpose is to do.
＜課題を解決するための手段＞ 上記の目的を達成するための構成を、実施例に対応する
第１図を参照しつつ説明すると、本発明では、基板１の
片面に、少なくとも一個の粒界ジョセフソン接合を持つ
高温超電導薄膜製のSQUIDリング２を形成し、かつ、そ
の裏面には一様な高温超電導薄膜産業上の３を形成し、
その基板１を、SQUIDリング２を内側にして円筒状に巻
回している。<Means for Solving the Problems> A structure for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. In the present invention, at least one grain boundary is provided on one surface of the substrate 1. SQUID ring 2 made of high temperature superconducting thin film with Josephson junction is formed, and uniform 3 on the high temperature superconducting thin film industry is formed on its back surface.
The substrate 1 is wound in a cylindrical shape with the SQUID ring 2 inside.
＜作用＞ 一つの基板１にSQUIDリング２とこれを取り囲む高温超
電導薄膜３が一体形成され、SQUIDリング２は高温超電
導薄膜３によってシールドされるので、別途シールドケ
ースを用意する必要がない。<Operation> Since the SQUID ring 2 and the high temperature superconducting thin film 3 surrounding the SQUID ring 2 are integrally formed on one substrate 1, and the SQUID ring 2 is shielded by the high temperature superconducting thin film 3, it is not necessary to separately prepare a shield case.
ここで、高温超電導体は、一般に、焼結体よりも薄膜状
に成長させたものの方が臨界電流密度が大幅に高く、シ
ールド効果が向上する。Here, the high-temperature superconductor generally has a significantly higher critical current density when grown in a thin film shape than the sintered body, and the shield effect is improved.
＜実施例＞ 第１図は本発明実施例の外観図である。<Example> FIG. 1 is an external view of an example of the present invention.
円筒状に巻かれたNgO基板１の内側には、多結晶のYBCO
薄膜による超電導リングの一部にマイクロブリッジ型の
粒界ジョセフソン接合を設けてなるSQUIDリング２が形
成されている。Inside the NgO substrate 1 wound in a cylindrical shape, polycrystalline YBCO
A SQUID ring 2 is provided in which a microbridge type grain boundary Josephson junction is provided in a part of a thin film superconducting ring.
この基板１の外側には、YBCO薄膜からなる高温超電導薄
膜３が形成されている。この超電導薄膜３は、粒界が存
在しないか、あるいは存在しても極めて僅かであり、実
質的に単結晶膜であって、その臨界電流密度は高い。A high temperature superconducting thin film 3 made of a YBCO thin film is formed on the outside of the substrate 1. This superconducting thin film 3 has no grain boundary or has very few grain boundaries, and is substantially a single crystal film, and its critical current density is high.
このような構造を持つSQUID素子では、内側のSQUIDリン
グ２は外側の高温超電導薄膜３によってシールドされ、
外部の磁気雑音の影響を受けない。In the SQUID element having such a structure, the inner SQUID ring 2 is shielded by the outer high temperature superconducting thin film 3,
Not affected by external magnetic noise.
以上の本発明実施例は、以下の手順によって製造するこ
とができる。The above-described embodiments of the present invention can be manufactured by the following procedure.
まず、厚さ0.5mmの適当な大きさのMgO基板１を用意し、
片面にSQUIDリング２の基になる適当な面積のYBCO薄膜
を製膜する。製膜方法は、スパッタ法、レーザーアブレ
ーション、あるいは反応性蒸着法等、公知の方法のうち
のいずれでもよい。この製膜にあっては、基板１の加熱
は行わない。First, prepare a MgO substrate 1 of a suitable size with a thickness of 0.5 mm,
A YBCO thin film having an appropriate area to be the base of the SQUID ring 2 is formed on one surface. The film forming method may be any of known methods such as a sputtering method, a laser ablation method, or a reactive vapor deposition method. In this film formation, the substrate 1 is not heated.
次いでそのYBCO薄膜をフォトリソグラフィの技術でパタ
ーニングして、SQUIDリング２の形状を作る。Next, the YBCO thin film is patterned by a photolithography technique to form the shape of the SQUID ring 2.
次に、その裏面に、同様な方法で比較的厚い、かつ、全
面にわたるYBCO薄膜を製膜する。Next, a YBCO thin film, which is relatively thick and covers the entire surface, is formed on the back surface by the same method.
この裏面側の製膜時には、基板１を加熱し、アズグロウ
ン膜とすることが望ましい。これによって、SQUIDリン
グ２の裏側に高温超電導薄膜３が形成されることにな
る。When forming the film on the back surface side, it is desirable to heat the substrate 1 to form an as-grown film. As a result, the high temperature superconducting thin film 3 is formed on the back side of the SQUID ring 2.
この状態を第２図に示す。This state is shown in FIG.
その後に、O2雰囲気下で800〜950℃でアニールし、SQUI
Dリング２を多結晶化して粒界ジョセフソン接合を得る
と同時に、このSQUIDリング２を内側にして基板１を巻
くように力に加えると、MgO基板１は曲がり、第１図に
示したシールド体（高温超電導薄膜）３とSQUIDリング
２が一体化された円筒状のSQUID素子が得られる。After that, anneal at 800-950 ℃ in O 2 atmosphere,
When the D ring 2 is polycrystallized to obtain the grain boundary Josephson junction, and at the same time when the SQUID ring 2 is placed inside and the substrate 1 is wound, the MgO substrate 1 bends and the shield shown in FIG. A cylindrical SQUID element in which the body (high-temperature superconducting thin film) 3 and the SQUID ring 2 are integrated is obtained.
なお、基板１としては、上記の実施例のように0.5mm程
度の厚さのMgO基板のほか、フィルム状のYSZ基板を使用
することができる。As the substrate 1, not only the MgO substrate having a thickness of about 0.5 mm as in the above embodiment, but also a film-shaped YSZ substrate can be used.
また、シールド体である高温超電導薄膜３は、必ずしも
基板１を加熱しながら製膜しなくてもよいが、基板加熱
を行った方が臨界電流密度が高くなってシールド効果が
より向上するという利点がある。Further, the high-temperature superconducting thin film 3 as a shield does not necessarily have to be formed while heating the substrate 1, but heating the substrate has the advantage that the critical current density becomes higher and the shielding effect is further improved. There is.
＜発明の効果＞ 以上説明したように、本発明によれば、SQUIDリングが
形成された基板の反対の面に、高温超電導薄膜を形成し
て、その基板を、SQUIDリングを内側にして円筒状に巻
回したので、SQUIDリングとシールド体が一体化されたS
QUID素子を実現できる。<Effects of the Invention> As described above, according to the present invention, a high-temperature superconducting thin film is formed on the surface opposite to the substrate on which the SQUID ring is formed, and the substrate is formed into a cylindrical shape with the SQUID ring inside. Since it is wound around, SQUID ring and shield body are integrated into S
A QUID element can be realized.
しかも、本発明の高温超電導薄膜によるシールド体で
は、特に単結晶の薄膜を使用した場合、従来のような高
温超電導体原料粉末を焼結したシールド体に比して、臨
界電流密度が大幅に高くなるので、そのシールド効果が
飛躍的に向上し、安定したSQUID素子となり得る。Moreover, in the shield body of the high temperature superconducting thin film of the present invention, particularly when a single crystal thin film is used, the critical current density is significantly higher than that of the conventional shield body obtained by sintering the high temperature superconductor raw material powder. Therefore, the shielding effect is dramatically improved, and it can be a stable SQUID element.
第１図は本発明実施例の外観図、第２図はその製造方法
の説明図である。 １……基板 ２……SQUIDリング ３……高温超電導薄膜FIG. 1 is an external view of an embodiment of the present invention, and FIG. 2 is an explanatory view of its manufacturing method. 1 …… Substrate 2 …… SQUID ring 3 …… High temperature superconducting thin film
Claims (1)
接合を持つ高温超電導薄膜製のSQUIDリングが形成さ
れ、かつ、その裏面には一様な高温超電導薄膜が形成さ
れた基板が、上記SQUIDリングを内側にして円筒状に巻
回されてなるSQUID素子。1. A substrate having a SQUID ring made of a high temperature superconducting thin film having at least one grain boundary Josephson junction on one surface and having a uniform high temperature superconducting thin film formed on the back surface thereof is the SQUID ring. A SQUID element that is wound in a cylindrical shape with the inside facing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1215204A JPH0675100B2 (en) | 1989-08-21 | 1989-08-21 | SQUID element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1215204A JPH0675100B2 (en) | 1989-08-21 | 1989-08-21 | SQUID element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0378674A JPH0378674A (en) | 1991-04-03 |
| JPH0675100B2 true JPH0675100B2 (en) | 1994-09-21 |
Family
ID=16668417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1215204A Expired - Lifetime JPH0675100B2 (en) | 1989-08-21 | 1989-08-21 | SQUID element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0675100B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4132720B2 (en) * | 2001-05-07 | 2008-08-13 | 独立行政法人科学技術振興機構 | Manufacturing method of quantum interference magnetometer |
-
1989
- 1989-08-21 JP JP1215204A patent/JPH0675100B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0378674A (en) | 1991-04-03 |
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