JPH0714080B2 - Superconductor processing method - Google Patents
Superconductor processing methodInfo
- Publication number
- JPH0714080B2 JPH0714080B2 JP62291419A JP29141987A JPH0714080B2 JP H0714080 B2 JPH0714080 B2 JP H0714080B2 JP 62291419 A JP62291419 A JP 62291419A JP 29141987 A JP29141987 A JP 29141987A JP H0714080 B2 JPH0714080 B2 JP H0714080B2
- Authority
- JP
- Japan
- Prior art keywords
- lbco
- plasma
- nitrogen
- superconductor
- single crystal
- 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
Links
- 239000002887 superconductor Substances 0.000 title description 7
- 238000003672 processing method Methods 0.000 title 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 17
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 239000010409 thin film Substances 0.000 claims description 4
- 239000000919 ceramic Substances 0.000 claims description 2
- 229910010293 ceramic material Inorganic materials 0.000 claims 1
- 239000013078 crystal Substances 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 8
- 239000010408 film Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 6
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- 239000001257 hydrogen Substances 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 3
- 229910002367 SrTiO Inorganic materials 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- OLBVUFHMDRJKTK-UHFFFAOYSA-N [N].[O] Chemical class [N].[O] OLBVUFHMDRJKTK-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910052747 lanthanoid Inorganic materials 0.000 description 1
- 150000002602 lanthanoids Chemical class 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910017464 nitrogen compound Inorganic materials 0.000 description 1
- 150000002830 nitrogen compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明は薄膜もしくはバルクの高温超伝導セラミックス
の加工方法に関する本発明は薄膜もしくはバルクの超伝
導体に対し、窒素プラズマによってその表面を選択的に
還元し、超伝導性を消失させることによって、超伝導デ
バイスを作らんとするものである。Description: FIELD OF THE INVENTION The present invention relates to a method for processing a thin film or bulk high-temperature superconducting ceramics. The present invention selectively processes the surface of a thin film or bulk superconductor by nitrogen plasma. It is intended to make a superconducting device by reducing and eliminating superconductivity.
高い臨界温度を有するLnBa2Cu3O6+X（Ln:ランタノイ
ド、０＜Ｘ＜１、以下これをLBCOと略す、特にLn＝Ｙの
ものをYBCOと略す） 一般に超伝導体はその材料が取るＸの値によって、その
超伝導性が大きく変化する。すなわちＸが１に近いとTc
が90K級の超伝導体となり、逆にＸが０に近いと超伝導
性が全く失われてしまう。この性質を利用してＸが０に
近いLBCOをプラズマ酸化して超伝導体化したり逆にＸが
１に近く超伝導性を示すLBCOを水素プラズマで還元し
て、非超電導体化したりすることによって表面を低温で
選択的に加工する方法が報告されている。LnBa 2 Cu 3 O 6 + X (Ln: lanthanoid, 0 <X <1, hereinafter abbreviated as LBCO, especially Ln = Y abbreviated as YBCO) having a high critical temperature. Generally, the material of a superconductor is The superconductivity changes greatly depending on the value of X taken. That is, when X is close to 1, Tc
Becomes a 90K-class superconductor, and conversely, when X is close to 0, superconductivity is completely lost. Utilizing this property, LBCO with X close to 0 is plasma-oxidized to be a superconductor, or LBCO showing superconductivity with X close to 1 is reduced with hydrogen plasma to be a non-superconductor. Have reported a method of selectively processing the surface at low temperature.
超伝導を示すLBCOを水素プラズマを用いて還元する場
合、還元反応によって必ず水が発生する。この場合生じ
た水がLBCO体内部に残るという問題点がある。LBCOは水
とはよく反応して分解するという性質があるため、水素
プラズマ還元によって生じた水はただちにLBCO外部へ取
り出されなければならない。しかし、そのためにLBCOを
加熱するとより一層、LBCO内部に存在する水とLBCOの反
応が進行してしまう。従って水素プラズマによる還元は
LBCOのごく表面でしか行えない。When LBCO showing superconductivity is reduced by using hydrogen plasma, water is always generated by the reduction reaction. In this case, there is a problem that the generated water remains inside the LBCO body. Since LBCO has the property of reacting well with water and decomposing, the water generated by hydrogen plasma reduction must be immediately extracted to the outside of LBCO. However, if LBCO is heated for that reason, the reaction between water and LBCO inside the LBCO will proceed further. Therefore, reduction by hydrogen plasma
It can be done only on the very surface of LBCO.
本発明は水素プラズマを用いずにLBCOを還元することに
よってLBCOと反応する水を生じさせず、超伝導体の表面
より奥の部分まで還元しようとするものである。そのた
め本発明では水素プラズマの代わりに窒素プラズマを用
いる、具体的には減圧下または大気圧のチャンバー内に
窒素ガスを封入するまたチャンバー内には還元すべき薄
膜状態またはバルクのLBCOを設置する。そしてチャンバ
ー内に直流または交流電源、または大出力マイクロ波電
源などによって窒素に電力を印加し、窒素プラズマを発
生させる。窒素プラズマは活性でさかんにLBCOの酸素と
反応して一酸化窒素もしくは二酸化窒素またはその他の
酸素窒素化合物となりLBCOは還元される。一酸化窒素や
二酸化窒素等の酸素窒素化合物はLBCOと反応しないた
め、たとえそれらがLBCO内部に残ってもLBCOは変性しな
い上、一酸化窒素や二酸化窒素はLBCOを減圧下で軽く加
熱するだけでLBCO外へ放出される。The present invention is intended to reduce LBCO without using hydrogen plasma to generate water that reacts with LBCO, and to reduce it to a portion deeper than the surface of the superconductor. Therefore, in the present invention, nitrogen plasma is used instead of hydrogen plasma. Specifically, nitrogen gas is enclosed in a chamber under reduced pressure or atmospheric pressure, and a thin film state or bulk LBCO to be reduced is installed in the chamber. Then, electric power is applied to nitrogen in the chamber by a DC or AC power source, a high-power microwave power source, or the like to generate nitrogen plasma. Nitrogen plasma is active and rapidly reacts with oxygen of LBCO to form nitric oxide or nitrogen dioxide or other oxygen-nitrogen compounds, and LBCO is reduced. Oxygen and nitrogen compounds such as nitric oxide and nitrogen dioxide do not react with LBCO, so even if they remain inside LBCO, LBCO does not denature, and nitric oxide and nitrogen dioxide can be heated by heating LBCO lightly under reduced pressure. Released outside LBCO.
以下、実施例に従い本発明を説明する。Hereinafter, the present invention will be described according to examples.
〔実施例１〕 本発明は実施例としてチタン酸ストロンチウム（SrTi
O3）単結晶（110）面上にスパッタ法により堆積させたY
BCO単結晶膜を用いた。これは減圧下（例えば100mtor
r）のアルゴン、酸素混合気体中でYBa2Cu3.6Oy（７＜ｙ
＜９）焼結体をターゲットとしてDCスパッタ法により成
膜したものであり、基板であるSrTiO3は約650℃に加熱
されている。このようにして約１μｍの膜厚のYBCO単結
晶膜が形成される。これは酸素中で約600℃、１時間加
熱することによって超伝導性を示すようになる。Example 1 The present invention is an example of strontium titanate (SrTi
O 3 ) Y deposited by sputtering on the (110) single crystal surface
A BCO single crystal film was used. This is under reduced pressure (eg 100mtor
r) in a mixed gas of argon and oxygen, YBa 2 Cu 3.6 Oy (7 <y
<9) A sintered body was formed as a target by the DC sputtering method, and the substrate SrTiO 3 was heated to about 650 ° C. In this way, a YBCO single crystal film having a thickness of about 1 μm is formed. It becomes superconducting by heating in oxygen at about 600 ° C for 1 hour.
第２図中の曲線（ａ）は、このときの抵抗の温度変化を
示す。The curve (a) in FIG. 2 shows the temperature change of the resistance at this time.
次にこの単結晶膜を第１図のような装置に入れた。４は
ガラス製もしくは金属製のチャンバーで左側の７はガラ
ス製の窓である。チャンバー内の圧力は排気のコンダク
タンス及び導入ガス流量によって調整される。この場
合、内部のガスは窒素とアルゴンを等モルずつ封入し、
全圧は100torrとした。この状態で７の窓から大出力マ
イクロ波電力をチャンバー内に導入すると容器内にプラ
ズマが発生した。このプラズマに対し、適当な支持棒３
にとりつけたSrTiO3上に成膜したYBCO単結晶膜５を近づ
けてゆく、プラズマに対し約1cmの近さまで近づけ、そ
の状態を約20時間保った。とり出したYBCO単結晶膜の抵
抗率の温度変化は第２図中の曲線（ｂ）である。かくし
て超伝導性を大幅に劣化させることができた。Next, this single crystal film was put into an apparatus as shown in FIG. 4 is a glass or metal chamber, and 7 on the left side is a glass window. The pressure in the chamber is adjusted by the conductance of exhaust gas and the flow rate of introduced gas. In this case, the gas inside contains nitrogen and argon in equimolar amounts,
The total pressure was 100 torr. In this state, when high-power microwave power was introduced into the chamber through the window 7, plasma was generated in the container. Suitable support rod 3 for this plasma
The YBCO single crystal film 5 formed on the SrTiO 3 attached to the above was brought closer to the plasma to a distance of about 1 cm, and that state was maintained for about 20 hours. The temperature change of the resistivity of the extracted YBCO single crystal film is a curve (b) in FIG. Thus, superconductivity could be significantly degraded.
〔実施例２〕 本発明を用いてトンネル型ジョセフソン接合素子を作製
した例を示す。第３図（ａ）の８はYBCOのバルク単結晶
であり、これは超伝導性を示す。この表面を〔実施例
１〕と同様の装置及び方法により約10時間窒素プラズマ
で還元すると表面から厚さ約5000Åの部分までが還元さ
れた（第３図（ｂ）の９）。Example 2 An example in which a tunnel type Josephson junction device is manufactured by using the present invention will be shown. Reference numeral 8 in FIG. 3 (a) is a YBCO bulk single crystal, which exhibits superconductivity. When this surface was reduced by nitrogen plasma for about 10 hours using the same apparatus and method as in [Example 1], the surface to a portion having a thickness of about 5000Å was reduced (9 in Fig. 3 (b)).
次に第１図の装置内に酸素とアルゴンの混合気体を導入
し、〔実施例１〕と同様にプラズマを発生させて、今後
は逆にプラズマ酸化を約15時間おこなうと表面から約40
00Åまでの部分が酸化され（第３図（ｃ）10）、結局約
1000Åの厚さの非超伝導層をはさんだトンネル型ジョセ
フソン接合ができた。この接合の77Kでの電流−電圧特
性は第４図のようになった。Next, a mixed gas of oxygen and argon was introduced into the apparatus shown in FIG. 1, plasma was generated in the same manner as in [Example 1], and conversely, when plasma oxidation was carried out for about 15 hours, about 40 from the surface.
The part up to 00Å is oxidized (Fig. 3 (c) 10), and eventually about
A tunnel type Josephson junction with a 1000 Å thick non-superconducting layer sandwiched was created. The current-voltage characteristics of this junction at 77K are as shown in Fig. 4.
本発明構成をとることによって、還元反応によって水分
等を発生させることがないので、超伝導材料内部にまで
還元処理を行うことができ還元反応処理後も、安定な超
伝導材料を提供することが可能となった。By adopting the configuration of the present invention, since water or the like is not generated by the reduction reaction, it is possible to perform the reduction treatment even inside the superconducting material, and to provide a stable superconducting material even after the reduction reaction treatment. It has become possible.
第１図はECRプラズマ発生装置の概念図を示す。 第２図は抵抗−温度曲線 （ａ）プラズマ還元する前のYBCO単結晶膜 （ｂ）プラズマ還元した後のYBCO単結晶膜 を示す。 第３図はプラズマ酸化−還元を用いたトンネル接合の形
成プロセス （ａ）加工前 （ｂ）表面をプラズマ還元したもの （ｃ）（ｂ）の表面をプラズマ酸化したものを示す。 第４図は第３図の方法により形成したトンネル接合の4.
2Kでの電圧−電流曲線を示す。FIG. 1 shows a conceptual diagram of the ECR plasma generator. FIG. 2 shows a resistance-temperature curve (a) YBCO single crystal film before plasma reduction (b) YBCO single crystal film after plasma reduction. FIG. 3 shows a tunnel junction forming process using plasma oxidation-reduction. (A) Before processing (b) Surface-reduced by plasma (c) (b) Surface-oxidized by plasma. Figure 4 shows the tunnel junction formed by the method of Figure 4.
The voltage-current curve at 2K is shown.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０１Ｂ 13/00 ＨＣＣ Ｚ 7244−5Ｇ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical indication H01B 13/00 HCC Z 7244-5G
Claims (1)
材料を窒素プラズマによって還元し、超伝導特性を失わ
せる、もしくは著しく劣化させることを特徴とする超伝
導セラミックスの加工方法。1. A method for processing superconducting ceramics, which comprises reducing a bulk or thin film superconducting ceramic material with nitrogen plasma to lose or significantly deteriorate superconducting characteristics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62291419A JPH0714080B2 (en) | 1987-11-17 | 1987-11-17 | Superconductor processing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62291419A JPH0714080B2 (en) | 1987-11-17 | 1987-11-17 | Superconductor processing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01132179A JPH01132179A (en) | 1989-05-24 |
| JPH0714080B2 true JPH0714080B2 (en) | 1995-02-15 |
Family
ID=17768636
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62291419A Expired - Lifetime JPH0714080B2 (en) | 1987-11-17 | 1987-11-17 | Superconductor processing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0714080B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6029235B2 (en) * | 1982-10-26 | 1985-07-09 | 日本電信電話株式会社 | Manufacturing method of superconducting circuit device |
| JPS6451684A (en) * | 1987-08-22 | 1989-02-27 | Idemitsu Kosan Co | Working method for superconducting material |
-
1987
- 1987-11-17 JP JP62291419A patent/JPH0714080B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01132179A (en) | 1989-05-24 |
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