JP2785263B2 - Superconductor manufacturing method - Google Patents
Superconductor manufacturing methodInfo
- Publication number
- JP2785263B2 JP2785263B2 JP63042649A JP4264988A JP2785263B2 JP 2785263 B2 JP2785263 B2 JP 2785263B2 JP 63042649 A JP63042649 A JP 63042649A JP 4264988 A JP4264988 A JP 4264988A JP 2785263 B2 JP2785263 B2 JP 2785263B2
- Authority
- JP
- Japan
- Prior art keywords
- superconductor
- barium
- copper
- temperature
- respect
- 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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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)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、常伝導状態での電気伝導性にすぐれ、しか
も同時に安定な超電導特性を有する超電導体の製造方法
の改良に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing a superconductor having excellent superconductivity in a normal state and at the same time having stable superconductivity.
従来の技術 最近、ランタニウム（La）−バリウム（Ba）−銅（C
u）−酸素（Ｏ）あるいはイットリウム（Ｙ）−Ba−Cu
−Ｏから成る酸化物導電体が高い超電導移点（Tc）を有
すると言う重要な発見が為された。Tcとしては構成元素
或は化合物組成の制御により30以上100K（−173℃）迄
の値が報告されている。特に、Ｙ−Ba−Cu−Ｏ系（以下
YBCOと略す）では、３金属の原子比率が1:2:3の時最も
高いTcが得られ、電気抵抗がゼロとなる温度（Toffと略
す）は、最も再現性のあるデータで、95Kであると言わ
れている。酸素の含有量に関しては、6.9程度であろう
と予想されている。更に、YBCO系でＹをランタニド系列
元素（例えば、Lu,Yb,Tm,Er,Ho,Dy,Gd,Eu,Sm,Nd,La）で
置き換えた化合物が多く合成されており、その大半が90
K以上のTcを示している。この様に、高い温度で超電導
を示す酸化物導電体は、Cu−Ｏを基本元素として含み、
イットリウムあるいはランタニド元素およびアルカリ土
類元素により結晶構造及び電子状態をうまく制御された
ものであると言える。2. Description of the Related Art Recently, lanthanum (La) -barium (Ba) -copper (C
u) -oxygen (O) or yttrium (Y) -Ba-Cu
An important finding has been made that the oxide conductor consisting of -O has a high superconducting transition point (Tc). It has been reported that Tc ranges from 30 to 100 K (-173 ° C.) by controlling the composition of constituent elements or compounds. In particular, Y-Ba-Cu-O (hereinafter referred to as Y-Ba-Cu-O)
In the case of YBCO, the highest Tc is obtained when the atomic ratio of the three metals is 1: 2: 3, and the temperature at which the electrical resistance becomes zero (abbreviated as Toff) is the most reproducible data. It is said that there is. It is expected that the oxygen content will be around 6.9. Further, many compounds in which Y is replaced by a lanthanide series element (for example, Lu, Yb, Tm, Er, Ho, Dy, Gd, Eu, Sm, Nd, La) in the YBCO system have been synthesized, and most of them have been synthesized.
It shows Tc of K or more. Thus, oxide conductors that exhibit superconductivity at high temperatures contain Cu-O as a basic element,
It can be said that the crystal structure and electronic state were well controlled by the yttrium or lanthanide element and the alkaline earth element.
また、極最近オブシンスキー氏らは、フッ素を含むＹ
−Ba−Cu−Ｏ系酸化物に於て150KのToffを認めている
（フィジカル レビュー レターズ;Phys.Rev.Lett.誌5
8巻2597頁（1987年））。更に、他の元素を添加するこ
とにより室温以上での超電導の兆しが見えたとの報告も
ある。更に、江原氏らはＹ−Ba−Sr−Cu−Ｏから成る酸
化物に於て、65℃で抵抗がゼロになる現象を報告してい
る（ジャパニーズ ジャーナル オブ ザ アプライド
フィジクス;Jpn.J.Appl.Phys.誌、26巻、頁、1987
年）。Most recently, Ovshinsky et al.
A Toff of 150 K is observed in -Ba-Cu-O-based oxides (Physical Review Letters; Phys. Rev. Lett. 5
8: 2597 (1987)). Furthermore, there is a report that the sign of superconductivity at room temperature or higher was observed by adding other elements. In addition, Ehara et al. Reported that the resistance of an oxide composed of Y-Ba-Sr-Cu-O became zero at 65 ° C (Japanese Journal of the Applied Physics; Jpn. J. Appl. .Phys., 26, 1987
Year).
一方、これらの超電導体がエレクトニクスデバイスと
して用いられるには超電導体が安定である事、超電導状
態で印加出来る電流密度が大きく取れる事などが大切で
ある。しかしながらセラミック超電導体の電流密度は超
電導体自体が粉体を焼結して製造されるため、その粉体
界面での抵抗のため大きく取れないのが普通である。On the other hand, in order for these superconductors to be used as an electronic device, it is important that the superconductor be stable and that a large current density can be applied in the superconducting state. However, the current density of the ceramic superconductor cannot be generally large because the superconductor itself is manufactured by sintering the powder and the resistance at the powder interface.
発明が解決しようとする課題 酸化物導電体の製造法は、焼結という固体反応に依存
しているため、その生成物は非晶質体か多結晶体である
ことが多い。従って、高温超電導を安定に出現させるに
は、化学組成ばかりでなく、焼結体の性質を制御する必
要がある。そのために、出発原料の粒径をできるだけ細
かくする事が先ず重要である。BaOの代わりにBaCO3を用
いるのはそのためであり、他の方法として、共沈法で沈
澱させた酸化物微粒子を用いるというのもある。また、
固体反応を効率よく進行させるために、原料を粉砕混合
した後に、粉末状態で長時間熱処理をする（仮焼）こと
が有効である。更に、焼結にあたっても、焼結温度、時
間、温度上昇−降下の制御、焼結雰囲気、特に関して細
かい制御が必要である。この様に従来の酸化物導電体の
製造法は、焼結体の性質を向上させるために非常に複雑
で、労を要する工法を必要としていた。Problems to be Solved by the Invention Since the method for producing an oxide conductor relies on a solid-state reaction called sintering, the product is often an amorphous substance or a polycrystalline substance. Therefore, in order to make high-temperature superconductivity appear stably, it is necessary to control not only the chemical composition but also the properties of the sintered body. Therefore, it is first important to make the particle size of the starting material as small as possible. That is why BaCO 3 is used instead of BaO, and another method is to use oxide fine particles precipitated by a coprecipitation method. Also,
In order to allow the solid reaction to proceed efficiently, it is effective to heat-treat (calcin) for a long time in a powder state after pulverizing and mixing the raw materials. Furthermore, in sintering, it is necessary to control the sintering temperature, time, control of temperature rise / fall, sintering atmosphere, and particularly the sintering atmosphere. As described above, the conventional method for manufacturing an oxide conductor requires a very complicated and labor-intensive method for improving the properties of the sintered body.
本発明は、上記のようなＹ−Ba−Cu−Ｏ系セラミック
ス超電導体の持つ課題を解決するもので、その目的の第
１は安定な超電導特性を示す超電導体を開発する事、第
２は高い電流密度を実現する事、第３は常伝導状態で電
気伝度度の高い材料を開発する事である。第３の点は万
一超電導状態が破れても発生する電流のジュール熱によ
って素子が破壊するのを防ぐために必要な特性である。The present invention solves the above-mentioned problems of the Y-Ba-Cu-O-based ceramic superconductor, and the first object of the present invention is to develop a superconductor exhibiting stable superconducting characteristics. The third is to realize a high current density, and to develop a material having a high electrical conductivity in a normal conduction state. The third point is a characteristic necessary for preventing the element from being destroyed by the Joule heat of the current generated even if the superconducting state is broken.
課題を解決するための手段 本発明は上記目的を達成するもので、請求項１記載の
超電導体の製造方法は、本質的にイットリウム、バリウ
ム、銅及び酸素から形成された超電導体の製造方法であ
って、前記バリウムの一部を前記バリウム100wt％に対
する置換量が10〜50wt％となるようにストロンチウムに
置換し、前記銅の一部を前記銅100wt％に対する置換量
が５〜25wt％となるように銀に置換する置換行程を有す
るものである。Means for Solving the Problems The present invention achieves the above object, and a method for manufacturing a superconductor according to claim 1 is a method for manufacturing a superconductor essentially formed of yttrium, barium, copper, and oxygen. Then, a part of the barium is replaced with strontium so that the replacement amount with respect to 100 wt% of barium is 10 to 50 wt%, and the replacement amount of part of the copper with respect to 100 wt% of copper is 5 to 25 wt%. As described above.
また、請求項２記載のように、置換行程後、更に、85
0℃〜945℃の間で焼成する焼成行程を有するものであっ
てもよい。Further, as described in claim 2, after the replacement step, 85
It may have a firing step of firing between 0 ° C and 945 ° C.
作用 本発明は、本質的にイットリウム、バリウム、銅及び
酸素から形成された超電導体の製造方法であって、前記
バリウムの一部を前記バリウム100wt％に対する置換量
が10〜50wt％となるようにストロンチウムに置換し、前
記銅の一部を前記銅100wt％に対する置換量が５〜25wt
％となるように銀に置換する置換行程を有する超電導体
の製造方法とする事により、安定で、高い電流密度と高
い常伝導状態における電導度を有する超電導体を得る事
が出来る。The present invention relates to a method for producing a superconductor essentially formed of yttrium, barium, copper and oxygen, wherein a part of the barium is substituted with 10 wt% to 50 wt% of the barium. Substitution with strontium, a part of the copper is substituted with 5 wt% to 25 wt% with respect to 100 wt% of the copper.
%, A superconductor having a stable, high current density and a high conductivity in a normal conduction state can be obtained by a method for producing a superconductor having a substitution process of substituting silver with silver.
実 施 例 本発明の超電導体の基本的な製造方法は次のとおりで
ある。メノウの乳鉢を用いて、最初に定められた組成比
〔Y:（Ba＋Sr）：（Cu＋Ag）の原子比率が1:2:3である
ことを基準にする〕のY2O3、BaCO3、SrCO3、CuO、Ag2O
を粉砕し、均一になるまで混合する。この時BaCO3とSrC
O33、CuOとAg2Oの重量比をいろいろに変化させる。粉砕
後、120℃以上の温度で十分に乾燥させ、成型を行う。
成型圧力は、500kg/cm3以上であれば良かったが焼結体
の均一性を考慮して、一般には2.5t/cm3の圧力で成型し
た。作られたペレットの焼成は、通常の管状炉を用い
て、空気中で行った。焼成温度は、850から945℃の間が
適当であった。焼成後、800℃に10時間、400℃に10時間
放置してアニールを施した。この様にして得られたＹ−
（Ba＋Sr）−（Cu＋Ag）−Ｏの焼結体は、添加物の量が
適当である場合には95Kで抵抗がゼロとなる超電導体で
あった。この超電導特性は非常に安定で、Sr及びAgを同
時に添加した系は室内に３ケ月間放置した後も安定な超
電導特性を示した。この様な安定な超電導特性を示し、
なおかつ先にのべたすぐれた電流密度、常伝導状態での
高伝導性が実現出来るのは、Ba100wt％に対するSrの添
加量が10〜50wt％、Cu100wt％に対するAgの添加量が５
〜25wt％の場合であった。表１にはCuに対するAgの添加
量を10wt％に固定した場合のBaに対するSrの添加量が、
超電導転移特性、電流密度、室温電気伝導度の値に及ぼ
す影響を示す。また表２にはBaに対するSrの添加量を20
wt％に固定した場合のCuに対するAgの添加量が超電導転
移特性、安定性、電流密度、室温電気伝導度の値に及ぼ
す影響を示す。EXAMPLE A basic method for manufacturing a superconductor of the present invention is as follows. Using a mortar of agate, Y 2 O 3 , BaCO 3 , and the composition ratio initially determined (based on the atomic ratio of Y: (Ba + Sr) :( Cu + Ag) being 1: 2: 3) SrCO 3 , CuO, Ag 2 O
Crush and mix until uniform. At this time, BaCO 3 and SrC
O 3 3, CuO and Ag 2 O variously changing the weight ratio of. After pulverization, it is sufficiently dried at a temperature of 120 ° C. or more, and molded.
The molding pressure may be 500 kg / cm 3 or more, but in consideration of the uniformity of the sintered body, molding is generally performed at a pressure of 2.5 t / cm 3 . The pellets thus produced were fired in air using a conventional tubular furnace. The firing temperature was suitably between 850 and 945 ° C. After firing, annealing was performed by leaving the film at 800 ° C. for 10 hours and at 400 ° C. for 10 hours. The Y- thus obtained
The sintered body of (Ba + Sr)-(Cu + Ag) -O was a superconductor having zero resistance at 95K when the amount of the additive was appropriate. The superconductivity was very stable, and the system to which Sr and Ag were added at the same time showed stable superconductivity even after being left indoors for three months. Showing such stable superconducting properties,
In addition, the above-mentioned excellent current density and high conductivity in a normal state can be realized only when the amount of Sr added is 10 to 50% by weight with respect to 100% by weight of Ba and the amount of Ag added is 5% with respect to 100% by weight of Cu.
2525 wt%. Table 1 shows the amount of Sr added to Ba when the amount of Ag added to Cu was fixed at 10 wt%.
The effects on superconducting transition characteristics, current density, and room temperature electrical conductivity are shown. Table 2 shows that the amount of Sr added to Ba
The effect of the addition amount of Ag to Cu on the value of superconducting transition characteristics, stability, current density, and room temperature electrical conductivity when fixed to wt% is shown.
表１の結果はSrの添加量が10〜50wt％時にすぐれた超電
導特性が得られる事を示している。また表２の結果はAg
の添加量が５〜25wt％の時にすぐれた超電導特性が得ら
れる事を示し、しかもAgの添加が電流密度の向上、室温
電気伝導度の向上に著るしい効果がある事を示してい
る。 The results in Table 1 show that excellent superconducting properties can be obtained when the amount of Sr added is 10 to 50 wt%. The result in Table 2 is Ag
Shows that excellent superconducting properties can be obtained when the addition amount is 5 to 25 wt%, and that addition of Ag has a remarkable effect on the improvement of current density and the improvement of room temperature electric conductivity.
以下にさらに詳細に述べる。 This will be described in more detail below.
〔実施例 １〕 試薬として入手したY2O3、Ba2O、Baに対し重量比が20
wt％に相当するSrを含むSrCO3、CuOおよびCuに対し重量
比が10wt％に相当するAgを含むAg2Oをメノウの乳鉢で高
純度エタノールを滴下しつつ、完全に粉砕した。[Example 1] The weight ratio of Y 2 O 3 , Ba 2 O and Ba obtained as reagents was 20
SrCO 3 containing Sr equivalent to wt%, CuO and Ag 2 O containing Ag equivalent to 10 wt% with respect to Cu were completely pulverized in an agate mortar while dropping high-purity ethanol.
この粉末を50gから10gの間の重さとして秤量し、直径
13cmの成型治具の中に充填し加圧した。圧力は約2500kg
/cm3で、排気しつつ30分間行った。このペレットを白金
板の上に置き置き、管状炉の中のにセットして熱処理を
行った。例えば、４時間の熱処理の結果、900℃では８
×104S/cmであった。最高の電導度は900から940℃の間
の温度で得られ、1.1×105から1.5×105S/cmであった。
また、945℃以上の温度では、抵抗が再び上昇する傾向
が見られた（例えば980℃で約７×103S/cm）。Weigh this powder as a weight between 50g and 10g, diameter
It was filled into a 13 cm molding jig and pressurized. Pressure is about 2500kg
This was performed for 30 minutes at / cm 3 with evacuation. The pellets were placed on a platinum plate, set in a tubular furnace, and heat-treated. For example, as a result of heat treatment for 4 hours, 8
× 10 4 S / cm. The highest conductivity was obtained at temperatures between 900 and 940 ° C., between 1.1 × 10 5 and 1.5 × 10 5 S / cm.
At a temperature of 945 ° C. or higher, the resistance tended to increase again (for example, about 7 × 10 3 S / cm at 980 ° C.).
この様にして得られたペレットに銀ペーストで四端子
電極を取りつけ、その超電導特性を測定した。温度−抵
抗特性の測定結果を図に示す。抵抗値は室温から597K付
近まで序々に減少し、97Kより急激に降下した。95K以下
ではゼロ抵抗を示し、完全な超電導状態になった。A four-terminal electrode was attached to the thus obtained pellet with a silver paste, and the superconducting characteristics were measured. The measurement results of the temperature-resistance characteristics are shown in the figure. The resistance gradually decreased from room temperature to around 597K, and dropped sharply from 97K. Below 95K, it exhibited zero resistance and became fully superconducting.
この様にして作成した超電導体は非常に安定であり、
空気中、室温で３ケ月間放置し、再び温度−抵抗特性を
測定したが全く変化していなかった。The superconductor made in this way is very stable,
It was left in the air at room temperature for 3 months, and the temperature-resistance characteristics were measured again, but no change was observed.
発明の効果 以上要するに、本質的にイットリウム、バリウム、銅
及び酸素から形成された超電導体の製造方法であって、
前記バリウムの一部を前記バリウム100wt％に対する置
換量が10〜50wt％となるようにストロンチウムに置換
し、前記銅の一部を前記銅100wt％に対する置換量が５
〜25wt％となるように銀に置換する置換行程を有する超
電導体の製造方法である本発明によって、すぐれた安定
性、高い電流密度、常伝導状態での高い電導度をかねて
そなえた超電導体を得る事が出来る。In summary, a method for manufacturing a superconductor essentially formed of yttrium, barium, copper and oxygen,
A part of the barium is replaced with strontium so that the replacement amount with respect to 100 wt% of barium is 10 to 50 wt%, and the replacement amount of a part of the copper is 5% with respect to 100 wt% of copper.
According to the present invention, which is a method for producing a superconductor having a substitution step of substituting silver to 2525 wt%, a superconductor having excellent stability, high current density and high conductivity in a normal conduction state can be obtained. You can get it.
図はＹ（Ba−Sr）（Cu−Ag）Ｏ系超電導体の温度−抵抗
特性である。The figure shows the temperature-resistance characteristics of the Y (Ba-Sr) (Cu-Ag) O-based superconductor.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C01G 1/00 ZAA──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. 6 , DB name) C01G 1/00 ZAA
Claims (2)
酸素から形成された超電導体の製造方法であって、前記
バリウムの一部を前記バリウム100wt％に対する置換量
が10〜50wt％となるようにストロンチウムに置換し、前
記銅の一部を前記銅100wt％に対する置換量が５〜25wt
％となるように銀に置換する置換行程を有する超電導体
の製造方法。1. A method for producing a superconductor essentially consisting of yttrium, barium, copper and oxygen, wherein a part of the barium is replaced by 10 to 50 wt% with respect to 100 wt% of the barium. Substitution with strontium, a part of the copper is substituted with 5 wt% to 25 wt% with respect to 100 wt% of the copper.
%. A method for producing a superconductor having a substitution process of substituting silver so as to be%.
成する焼成行程を有する請求項１記載の超電導体の製造
方法。2. The method for producing a superconductor according to claim 1, further comprising a firing step of firing at a temperature between 850 ° C. and 945 ° C. after the replacement step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63042649A JP2785263B2 (en) | 1988-02-25 | 1988-02-25 | Superconductor manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63042649A JP2785263B2 (en) | 1988-02-25 | 1988-02-25 | Superconductor manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01215713A JPH01215713A (en) | 1989-08-29 |
| JP2785263B2 true JP2785263B2 (en) | 1998-08-13 |
Family
ID=12641858
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63042649A Expired - Lifetime JP2785263B2 (en) | 1988-02-25 | 1988-02-25 | Superconductor manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2785263B2 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01221810A (en) * | 1987-10-23 | 1989-09-05 | Furukawa Electric Co Ltd:The | Oxide superconductive mold and its manufacture |
| JPH01153525A (en) * | 1987-12-11 | 1989-06-15 | Tokin Corp | Oxide superconductor of ag fine particle-containing oxygen deficient triple structure perovskite type and production thereof |
| JPH01164730A (en) * | 1987-12-22 | 1989-06-28 | Tanaka Kikinzoku Kogyo Kk | Superconducting material and its production |
| JPH01192760A (en) * | 1988-01-28 | 1989-08-02 | Tokin Corp | Ag2o3-containing oxide superconductor and production thereof |
-
1988
- 1988-02-25 JP JP63042649A patent/JP2785263B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01215713A (en) | 1989-08-29 |
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