JPH0521848B2 - - Google Patents
Info
- Publication number
- JPH0521848B2 JPH0521848B2 JP63281909A JP28190988A JPH0521848B2 JP H0521848 B2 JPH0521848 B2 JP H0521848B2 JP 63281909 A JP63281909 A JP 63281909A JP 28190988 A JP28190988 A JP 28190988A JP H0521848 B2 JPH0521848 B2 JP H0521848B2
- Authority
- JP
- Japan
- Prior art keywords
- superconducting
- temperature
- composition
- materials
- oxide
- 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 - Fee Related
Links
- 239000000203 mixture Substances 0.000 claims description 10
- 239000002887 superconductor Substances 0.000 claims description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 239000000843 powder Substances 0.000 claims 1
- 239000000463 material Substances 0.000 description 14
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 230000007704 transition Effects 0.000 description 4
- 229910002480 Cu-O Inorganic materials 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229960004643 cupric oxide Drugs 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005404 magnetometry Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910014454 Ca-Cu Inorganic materials 0.000 description 1
- 229910004247 CaCu Inorganic materials 0.000 description 1
- 241000238366 Cephalopoda Species 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 1
- UFQXGXDIJMBKTC-UHFFFAOYSA-N oxostrontium Chemical compound [Sr]=O UFQXGXDIJMBKTC-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- LPHBARMWKLYWRA-UHFFFAOYSA-N thallium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Tl+3].[Tl+3] LPHBARMWKLYWRA-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Description
（産業上の利用分野）
本発明は、各種の超伝導応用装置や超伝導素子
に使用される酸化物超伝導材料に関するものであ
る。
（従来の技術）
現在、超伝導材料としては、すでに金属・合金
系超伝導材料、化合物超伝導材料などが実用化さ
れている。超伝導材料は超伝導磁石用のコイルや
ジヨセフソン素子などのエレクトロニクスデバイ
スなどを作るのに用いられ、特にジヨセフソン接
合の高感度性、高精度性、低雑音性を利用した
SQUIDや精密計測への応用の他、ジヨセフソン
接合の高速応答性と低消費電力性に着目した電子
計算機への応用が期待されている。
超伝導材料の超伝導転移温度Tcは、できるだ
け高いことが望まれるが、30KのTcを持つLa−
Ba−Cu−Ｏ系酸化物超伝導体の発見以来、90K
級のBa−Ｙ−Cu−Ｏ系、110K級のBi−Sr−Ca
−Ｏ系、120K級のTl−Ba−Ca−Cu−Ｏ系など
が相次いで発見されてきた。液体窒素温度をはる
かに越えたTcをもつ材料の発見は、実用材料と
しての期待をますます高めている。
（発明が解決しようとする問題点）
超伝導材料をエレクトロニクスデバイスに応用
する際にはプロセス中の最高温度が低いことが望
ましい。また臨界電流密度Jcが大きいことも配線
材料を考える上で重要である。Tl−Ba−Ca−Cu
系超伝導体は、100K以上の超伝導転移温度を有
する材料であるが、高いJcを得るためには、焼成
に890−910℃の温度が必要であり、それよりも低
い温度で焼成した場合には、焼結が進まないため
にJcが小さくなつてしまう。そこで本発明の目的
は、従来のものよりも低い最適焼成温度を持ち、
かつこれまで高い焼成温度でのみ得られていたよ
うな高いJcを持つ超伝導体を提供することにあ
る。
（問題点を解決するための手段）
本発明は酸化物超伝導材料、特に従来の
Tl2Ba2Cao-1CuoOy（ｎ＝１、２、３）とは異なる
TlSr4-xYxCu3Oyなる組成式で0.1≦ｘ≦2.0なる組
成を860℃〜880℃で焼結すれば高いJcを持つ焼結
体が得られること、及び焼結の際にプレス成形体
を金箔で包むことにより上記組成物の特性がさら
に向上することを見いだしたものである。
（作用）
Tl2Ba2CaCu2Oyでは870℃で１時間焼結した時
の、77KにおけるJcは100A／cm2であつた。しか
るにTlSr3YCu2Oyでは同一焼成条件で、900A／
cm2のJcを持つ厳密な焼結体が得られた。この焼結
体は100Kで、シヤープに超伝導転移を起こし、
転移後は全体積の約80％が超伝導状態になつてい
ることが確認された。
（実施例）
以下実施例により、本発明を具体的に説明す
る。出発原料として純度99％以上の酸化タリウム
（Tl2O3）、酸化ストロンチウム（SrO）、酸化イツ
トリウム（Y2O3）、酸化第２銅（CuO）を使用し
第１表に示す配合比になるように各々秤量した。
次に秤量した各材料を乳鉢でよく混合した後、プ
レスして５mm×10mm×１mmのプレス体を作成し
た。このプレス体を酸素雰囲気中で860℃〜880℃
で１〜10時間焼成した。また一部の試料について
は金箔で包んで焼成した。第１表の範囲の焼結体
について抵抗率、臨界電流密度、超伝導体積分率
の測定を行い超伝導特性を評価した。
抵抗率は直流４端子法によつて行つた。電極は
金をスパツタリング法にて取り付けリードとして
錫メツキ銅線を用いた。
臨界電流密度も直流４端子法により求めた。電
圧端子間に0.1μV以上の電圧が生じたときの電流
をJcとした。
超伝導体積分率は交流帯磁率測定より求めた。
交流帯磁率はコイルの中にサンプルをいれコイ
ルのＬの変化を測定することによつて行つた。体
積分率は、同体積、同じ形状の鉛の4.2Kにおけ
るΔLを100として算出した。抵抗測定は室温から
抵抗が０になる温度まで、帯磁率測定は室温から
4.2Kまで行つた。
第１表に配合比と抵抗が０になる臨界温度、
77Kでの臨界電流密度を示す。本発明による試料
は従来より低い温度で焼成しても大きなJcが得ら
れる。また金箔で包んで焼成した場合にはさらに
数％特性値が向上した。ただしｘが0.1未満では、
超伝導特性を示さず本発明の目的には不適当であ
る。またｘが2.0を越えると体積分率が減り、Jc
も小さくなつてしまう。また焼成温度が860℃〜
880℃範囲外では焼結性が悪くなるか又は体積分
率が減少してしまう。
(Field of Industrial Application) The present invention relates to oxide superconducting materials used in various superconducting application devices and superconducting elements. (Prior Art) Currently, as superconducting materials, metal/alloy superconducting materials, compound superconducting materials, etc. have already been put into practical use. Superconducting materials are used to make electronic devices such as coils for superconducting magnets and Josephson elements, and are particularly useful for making use of the high sensitivity, high precision, and low noise properties of Josephson junctions.
In addition to applications in SQUIDs and precision measurements, it is expected to be applied to electronic computers that take advantage of the Josephson junction's high-speed response and low power consumption. The superconducting transition temperature Tc of superconducting materials is desired to be as high as possible, but La−
Since the discovery of Ba-Cu-O based oxide superconductor, 90K
grade Ba-Y-Cu-O system, 110K grade Bi-Sr-Ca
-O series, 120K class Tl-Ba-Ca-Cu-O series, etc. have been discovered one after another. The discovery of a material with a Tc that far exceeds the temperature of liquid nitrogen has raised expectations for its potential as a practical material. (Problems to be Solved by the Invention) When applying superconducting materials to electronic devices, it is desirable that the maximum temperature during the process be low. It is also important when considering wiring materials that the critical current density Jc is large. Tl−Ba−Ca−Cu
A system superconductor is a material with a superconducting transition temperature of 100K or more, but in order to obtain a high Jc, a temperature of 890-910℃ is required for firing, and if fired at a lower temperature In this case, Jc becomes small because sintering does not proceed. Therefore, the purpose of the present invention is to have an optimal firing temperature lower than that of conventional ones,
Another object of the present invention is to provide a superconductor having a high Jc that has hitherto been obtained only at high sintering temperatures. (Means for Solving the Problems) The present invention relates to oxide superconducting materials, particularly conventional
Different from Tl 2 Ba 2 Ca o-1 Cu o O y (n=1, 2, 3)
It is known that a sintered body with a high Jc can be obtained by sintering a composition with a composition formula of TlSr 4-x Y x Cu 3 O y and a composition of 0.1≦x≦2.0 at 860℃ to 880℃, and that during sintering, It has been discovered that the properties of the above composition can be further improved by wrapping the press-molded body with gold foil. (Function) When Tl 2 Ba 2 CaCu 2 O y was sintered at 870°C for 1 hour, Jc at 77K was 100A/cm 2 . However, for TlSr 3 YCu 2 O y , 900A/
A strictly sintered body with Jc of cm 2 was obtained. This sintered body undergoes a sharp superconducting transition at 100K,
It was confirmed that approximately 80% of the total volume was in a superconducting state after the transition. (Example) The present invention will be specifically described below with reference to Examples. Thallium oxide (Tl 2 O 3 ), strontium oxide (SrO), yttrium oxide (Y 2 O 3 ), and cupric oxide (CuO) with a purity of 99% or higher were used as starting materials, and the mixture ratios shown in Table 1 were obtained. Each was weighed so that
Next, the weighed materials were thoroughly mixed in a mortar and then pressed to create a pressed body of 5 mm x 10 mm x 1 mm. This pressed body is heated at 860℃ to 880℃ in an oxygen atmosphere.
Baked for 1 to 10 hours. Some samples were wrapped in gold foil and fired. The resistivity, critical current density, and superconducting volume fraction of the sintered bodies in the range shown in Table 1 were measured to evaluate the superconducting properties. Resistivity was measured by the DC 4-terminal method. Gold was attached to the electrodes by sputtering, and tin-plated copper wire was used as the lead. The critical current density was also determined by the DC four-probe method. The current when a voltage of 0.1 μV or more was generated between the voltage terminals was defined as Jc. The superconducting volume fraction was determined by AC magnetic susceptibility measurement. AC magnetic susceptibility was measured by placing a sample in a coil and measuring the change in L of the coil. The volume fraction was calculated by setting ΔL at 4.2K of lead of the same volume and shape as 100. Resistance measurement is from room temperature to the temperature where resistance becomes 0. Magnetic susceptibility measurement is from room temperature.
I made it to 4.2K. Table 1 shows the compounding ratio and the critical temperature at which resistance becomes 0.
Critical current density at 77K is shown. The sample according to the present invention can obtain a large Jc even if it is fired at a lower temperature than the conventional one. Furthermore, when wrapped in gold foil and fired, the characteristic values were further improved by several percent. However, when x is less than 0.1,
It exhibits no superconducting properties and is unsuitable for the purpose of the present invention. Also, when x exceeds 2.0, the volume fraction decreases and Jc
It also becomes smaller. Also, the firing temperature is 860℃ ~
If the temperature is outside the 880°C range, sinterability will deteriorate or the volume fraction will decrease.
【表】
（発明の効果）
本発明の組成物は、低温で焼成を行つても高い
臨界電流密度を持つため、超伝導材料として非常
に実用性の高いものである。[Table] (Effects of the Invention) The composition of the present invention has a high critical current density even when fired at a low temperature, so it is highly practical as a superconducting material.
Claims (1)
成物において0.1≦Ｘ≦2.0なる範囲にあることを
特徴とする酸化物超伝導体組成物。 ２ Tl2O3、SrO、Y2O3、CuO粉末を特許請求の
範囲第１項記載の組成となるように混合し、プレ
ス成形した後、860℃から880℃の温度範囲で金箔
で包み熱処理することを特徴とする酸化物超伝導
体組成物の製造方法。[Scope of Claims] 1. An oxide superconductor composition expressed as TlSr 4-x Y x Cu 3 O y , characterized in that the oxide superconductor composition is in the range of 0.1≦X≦2.0. 2 Tl 2 O 3 , SrO, Y 2 O 3 , and CuO powders are mixed to have the composition described in claim 1, press-molded, and then wrapped in gold foil at a temperature range of 860°C to 880°C. 1. A method for producing an oxide superconductor composition, comprising heat treatment.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63281909A JPH02129025A (en) | 1988-11-07 | 1988-11-07 | Oxide superconductor composition and production thereof |
| EP89117902A EP0362685B1 (en) | 1988-09-28 | 1989-09-27 | An oxide superconductor composition and a process for the production thereof |
| DE8989117902T DE68904858T2 (en) | 1988-09-28 | 1989-09-27 | OXIDIC SUPER LADDER AND METHOD FOR THE PRODUCTION THEREOF. |
| US07/413,237 US5328892A (en) | 1988-09-28 | 1989-09-27 | Oxide superconductor composition and a process for the production thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63281909A JPH02129025A (en) | 1988-11-07 | 1988-11-07 | Oxide superconductor composition and production thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02129025A JPH02129025A (en) | 1990-05-17 |
| JPH0521848B2 true JPH0521848B2 (en) | 1993-03-25 |
Family
ID=17645645
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63281909A Granted JPH02129025A (en) | 1988-09-28 | 1988-11-07 | Oxide superconductor composition and production thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02129025A (en) |
-
1988
- 1988-11-07 JP JP63281909A patent/JPH02129025A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02129025A (en) | 1990-05-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |