JPH02120234A - Production of oxide superconductor - Google Patents
Production of oxide superconductorInfo
- Publication number
- JPH02120234A JPH02120234A JP63272459A JP27245988A JPH02120234A JP H02120234 A JPH02120234 A JP H02120234A JP 63272459 A JP63272459 A JP 63272459A JP 27245988 A JP27245988 A JP 27245988A JP H02120234 A JPH02120234 A JP H02120234A
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- oxide superconductor
- critical temperature
- temperature phase
- superconductor
- 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.)
- Pending
Links
- 239000002887 superconductor Substances 0.000 title claims abstract description 76
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 239000000843 powder Substances 0.000 claims abstract description 34
- 239000000203 mixture Substances 0.000 claims abstract description 27
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- 239000002994 raw material Substances 0.000 claims abstract description 11
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 claims abstract 4
- 238000000034 method Methods 0.000 claims description 12
- 238000002156 mixing Methods 0.000 claims description 10
- 229910052791 calcium Inorganic materials 0.000 claims description 7
- 239000000126 substance Substances 0.000 abstract description 7
- 238000002441 X-ray diffraction Methods 0.000 description 14
- 239000011812 mixed powder Substances 0.000 description 10
- 229910000019 calcium carbonate Inorganic materials 0.000 description 8
- 239000007858 starting material Substances 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- 238000001354 calcination Methods 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910014454 Ca-Cu Inorganic materials 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 235000010216 calcium carbonate Nutrition 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052745 lead Inorganic materials 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- LEDMRZGFZIAGGB-UHFFFAOYSA-L strontium carbonate Chemical compound [Sr+2].[O-]C([O-])=O LEDMRZGFZIAGGB-UHFFFAOYSA-L 0.000 description 3
- 229910000018 strontium carbonate Inorganic materials 0.000 description 3
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- WMWLMWRWZQELOS-UHFFFAOYSA-N bismuth(III) oxide Inorganic materials O=[Bi]O[Bi]=O WMWLMWRWZQELOS-UHFFFAOYSA-N 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 101100296543 Caenorhabditis elegans pbo-4 gene Proteins 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- -1 organic acid salts Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000005303 weighing Methods 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
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−０系の酸化物超電
導体の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a Bi-Sr-Ca-Cu-0 based oxide superconductor.
（従来の技術）
１９８６年に４０に以上の高い臨界温度を有するＬａ−
Ｂａ−Ｃｕ−０系の層状ペロブスカイト型の酸化物系超
電導体が発表されて以来、酸化物系の超電導材料が注目
を集めた。また、１９８７年にはＹ−Ｂａ−Ｃｕ−０系
で代表される酸素欠陥を有する欠陥ペロブスカイト型の
酸化物超電導体の臨界温度が液体窒素温度（−７７Ｋ）
より高い、約９０にであることが確認された。この発見
により冷媒として高価な液体ヘリウムに代えて、より安
価な液体窒素を用いた超電導体の応用が可能となり、各
所で盛んに研究が行われている。(Prior art) In 1986, La-
Since the Ba-Cu-0 layered perovskite type oxide superconductor was announced, oxide superconducting materials have attracted attention. Furthermore, in 1987, the critical temperature of a defective perovskite-type oxide superconductor with oxygen defects represented by the Y-Ba-Cu-0 system was determined to be the liquid nitrogen temperature (-77K).
It was found to be higher, around 90. This discovery has made it possible to apply superconductors using cheaper liquid nitrogen instead of expensive liquid helium as a refrigerant, and research is being actively conducted in various places.
また、１９８８年には臨界温度が１０５に近辺と高いＢ
ｉ−Ｓｒ−Ｃａ−Ｃｕ−０系の酸化物超電導体が発見さ
れるに至った。このＢｉ−８ｒ−Ｃａ−Ｃｕ−０系の酸
化物超電導体は、Ｙ−Ｂａ−Ｃｕ−０系の酸化物超電導
体に比べて臨界温度が高く、たとえば液体窒素によって
冷却を行う際に実用上充分な熱的マージンがとれるばか
りでなく、高価な希土類元素が不要であること、水分に
対する化学的安定性が高いこと、酸素が抜けにくいこと
などの利点があり、より優れた超電導体として注目を集
めている。In addition, in 1988, the critical temperature of B was as high as around 105.
An i-Sr-Ca-Cu-0 based oxide superconductor has been discovered. This Bi-8r-Ca-Cu-0-based oxide superconductor has a higher critical temperature than the Y-Ba-Cu-0-based oxide superconductor, making it difficult to use in practical applications when cooling with liquid nitrogen, for example. It is attracting attention as a superior superconductor because it not only provides a sufficient thermal margin, but also eliminates the need for expensive rare earth elements, has high chemical stability against moisture, and is difficult for oxygen to escape. are collecting.
ところで、このＢｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超
電導体には、零抵抗を示す臨界温度（以下、Ｔｃｅｎｄ
と記す。）が約８０にの化学式
％式％（１）
で表される低臨界温度相と、Ｔｃｅｎｄが約１ｌＯＫの
化学式
％式％）
で表される高臨界温度相の２種類の超電導相が存在して
いることが確認されている。また、このＢｉ−８ｒ−Ｃ
ａ−Ｃｕ−０系酸化物超電導体は、Ｙ−Ｂａ−Ｃｕ−０
系酸化物超電導体などと同様に結晶性の酸化物であるた
め、たとえばＢｉ２０３ 、ＳｒＣＯ３、ＣａＣＯ３、
ＣｕＯなどの粉末を原料粉として用いた、通常の焼成法
によって作製することが試みられているが、このような
方法によって得られたＢｉ−３ｒ−Ｃａ−Ｃｕ−０系酸
化物超電導焼結体は上記低臨界温度相と高臨界温度相と
が混在したものとして得られるため、Ｔｃｅｎｄは８０
に程度の低いものしか得られていないのが現状である。By the way, this Bi-8r-Ca-Cu-0 based oxide superconductor has a critical temperature (hereinafter referred to as Tcend) at which it exhibits zero resistance.
It is written as There are two types of superconducting phases: a low critical temperature phase represented by the chemical formula % formula % (1) where Tcend is approximately 80 and a high critical temperature phase represented by the chemical formula % formula %) where Tcend is approximately 1lOK. It has been confirmed that Also, this Bi-8r-C
The a-Cu-0 based oxide superconductor is Y-Ba-Cu-0
Since it is a crystalline oxide like other oxide superconductors, for example, Bi203, SrCO3, CaCO3,
Attempts have been made to produce a Bi-3r-Ca-Cu-0 based oxide superconducting sintered body using a normal sintering method using powder such as CuO as a raw material powder. is obtained as a mixture of the above-mentioned low critical temperature phase and high critical temperature phase, so Tcend is 80
At present, only a low level of results has been obtained.
また、Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体を
溶融凝固法によって作製することにより、高密度の酸化
物超電導体が得られ、臨界電流密度の向上などに効果が
あるものの、このような場合においても上述した焼成法
によって得られる酸化物超電導焼結体と同様に高臨界温
度相と低臨界温度相とが混在するものしか得られていな
い。In addition, high-density oxide superconductors can be obtained by fabricating Bi-8r-Ca-Cu-0 based oxide superconductors by the melt-solidification method, which is effective in improving critical current density. Even in such a case, only a mixture of a high critical temperature phase and a low critical temperature phase can be obtained, similar to the oxide superconducting sintered body obtained by the above-mentioned sintering method.
このような問題に対して、Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−０
系酸化物超電導体にＰｂを添加し、Ｂｉの一部をＰｂて
置換することによって、高臨界温度相の体積比を大幅に
増加することができるという報告がある。For such problems, Bi-Sr-Ca-Cu-0
There is a report that the volume ratio of the high critical temperature phase can be significantly increased by adding Pb to a system oxide superconductor and substituting a part of Bi with Pb.
しかしながら、上述した焼成法によってＢｉ−８ｒ−Ｃ
ａ−Ｃｕ−０系酸化物超電導体を作製する際に、Ｐｂを
たとえば酸化物と添加したとしても、Ｐｂの酸化物は蒸
気圧が高いために熱処理時に揮散しやすく、組成の制御
が非常に難しいという問題がある。よって、酸化物超電
導体の原料粉末にＰｂの酸化物を添加しただけでは、高
臨界温度相を再現性よくかつ効率よく得ることができな
い。また、溶融凝固法などを使用する場合においては、
特に溶融時にＰｂが蒸発してしまい、結果的にほぼ低臨
界温度相しか生成しない。However, by the above-mentioned firing method, Bi-8r-C
Even if Pb is added with an oxide when producing an a-Cu-0-based oxide superconductor, the Pb oxide has a high vapor pressure and easily evaporates during heat treatment, making it extremely difficult to control the composition. The problem is that it is difficult. Therefore, simply by adding Pb oxide to the raw material powder of the oxide superconductor, a high critical temperature phase cannot be obtained with good reproducibility and efficiency. In addition, when using the melt solidification method,
In particular, Pb evaporates during melting, resulting in almost only a low critical temperature phase being generated.
（発明が解決しようとする課題）
上述したように、Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物
超電導体は、低臨界温度相と高臨界温度相とが混在した
ものとして得られるため、高臨界温度相の特性を生かす
ことができないという向題があった。(Problems to be Solved by the Invention) As mentioned above, the Bi-8r-Ca-Cu-0 based oxide superconductor is obtained as a mixture of a low critical temperature phase and a high critical temperature phase. The problem was that it was not possible to take advantage of the characteristics of the critical temperature phase.
また、Ｂｉの一部をＰｂで置換することによって高臨界
温度相の生成比率を高めるという報告もなされているが
、この方法は焼成時における組成制御が極めて難しく、
再現性に乏しいという問題があった。It has also been reported that replacing a portion of Bi with Pb increases the production ratio of the high critical temperature phase, but this method is extremely difficult to control the composition during firing;
There was a problem of poor reproducibility.
本発明は、このような従来技術の課題に対処するために
なされたもので、Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物
超電導体の低臨界温度相を高臨界温度相に効率よく変換
し、高臨界温度相の比率が高いＢｉ−８ｒ−Ｃａ−Ｃｕ
−０系酸化物超電導体、さらには高臨界温度相単一相の
Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体を再現性
よく得ることを可能にした酸化物超電導体の製造方法を
提供することを目的としている。The present invention has been made to address the problems of the prior art, and is a method for efficiently converting the low critical temperature phase of a Bi-8r-Ca-Cu-0 based oxide superconductor into a high critical temperature phase. , Bi-8r-Ca-Cu with a high ratio of high critical temperature phase
A method for producing an oxide superconductor that makes it possible to obtain a Bi-8r-Ca-Cu-0-based oxide superconductor with a high critical temperature single phase with good reproducibility. is intended to provide.
［発明の構成］
（課題を解決するための手段）
すなわち、本発明の酸化物超電導体の製造方法の第１の
発明は、（Ａ ） Ｂｉ−３ｒ−Ｃａ−Ｃｕ−０系酸
化物超電導体、加熱により前記Ｂｉ−８ｒ−Ｃａ−Ｃｕ
−０系酸化物超電導体となる原料粉末、前記酸化物超電
導体よりもＣａの含有量が少ない酸化物、加熱により前
記酸化物となる原料粉末から選ばれた少なくとも １種
と、（Ｂ） Ｃａ２ Ｐｂ０４またはＣａ２ Ｐｂ０４
とＣｕの酸化物との混合物とを混合あるいは接触させ、
その状態で熱処理することを特徴としている。[Structure of the Invention] (Means for Solving the Problem) That is, the first invention of the method for producing an oxide superconductor of the present invention is (A) Bi-3r-Ca-Cu-0 based oxide superconductor , by heating the Bi-8r-Ca-Cu
- At least one selected from a raw material powder that becomes a 0-based oxide superconductor, an oxide with a lower Ca content than the oxide superconductor, and a raw material powder that becomes the oxide upon heating, and (B) Ca2. Pb04 or Ca2 Pb04
and a mixture of Cu oxide,
It is characterized by being heat-treated in that state.
また、第２の発明は、（Ｃ） Ｂｉ、 （Ｓｒ、Ｃａ）
、Ｃｕを原子比でおおよそ２：３：２で含有する酸化
物超電導体と、（Ｄ）Ｃａの酸化物とＰｂの酸化物との
混合物またはＣａの酸化物とＰｂの酸化物とＣｕの酸化
物との混合物とを混合あるいは接触させ、その状態で熱
処理することを特徴としている。Moreover, the second invention is (C) Bi, (Sr, Ca)
, an oxide superconductor containing Cu in an atomic ratio of approximately 2:3:2, and (D) a mixture of a Ca oxide and a Pb oxide or an oxide of a Ca oxide, a Pb oxide, and a Cu oxide. It is characterized by mixing or contacting a mixture with a substance and heat-treating it in that state.
本発明の第１の酸化物超電導体の製造方法における一方
の出発原料となる（Ａ）成分としては、■ 低臨界温度
相を主とするＢｉ−Ｓｒ−Ｃａ−Ｃｕ−０系酸化物超電
導体の焼結体や粉末、
■ 加熱により上記■のＢｉ−８ｒ−Ｃａ−Ｃｕ−０系
酸化物超電導体となる原料粉末、
■ 前記酸化物超電導体よりもＣａの含有量が少ない酸
化物の焼結体や粉末、
■ 加熱により上記■の化合物となる原料粉末の少なく
とも １種が用いられる。The component (A), which is one of the starting materials in the first method for producing an oxide superconductor of the present invention, includes (1) a Bi-Sr-Ca-Cu-0 based oxide superconductor mainly having a low critical temperature phase; (1) raw material powder that becomes the Bi-8r-Ca-Cu-0 based oxide superconductor of (2) above by heating; (2) sintered oxide with a lower Ca content than the oxide superconductor; At least one of the following is used: solids, powder, and (1) raw material powder that becomes the compound (2) above when heated.
上記■としては、旧、Ｓｒｓ Ｃａ５Ｃｕの単体または
化合物を所定のモル比で混合したものが用いられる。こ
れら構成元素の化合物としては、炭酸塩や酸化物を用い
ることができる他、炭酸塩以外の加熱により酸化物に転
化する硝酸塩、水酸化物など、さらに有機酸塩や有機金
属などを用いてもよい。As the above-mentioned (2), a mixture of Srs Ca5Cu alone or a compound at a predetermined molar ratio is used. As compounds of these constituent elements, carbonates and oxides can be used, as well as nitrates and hydroxides that convert into oxides by heating other than carbonates, and organic acid salts and organic metals. good.
これらＢｊ−Ｓｒ−Ｃａ−Ｃｕ−０系酸化物超電導体の
構成元素は、基本的に超電導体相の原子比を満足するよ
うに混合するが、製造条件との関係で多少、たとえば１
０％程度ずれていても差支えない。The constituent elements of these Bj-Sr-Ca-Cu-0-based oxide superconductors are basically mixed to satisfy the atomic ratio of the superconductor phase, but depending on the manufacturing conditions, for example, 1
There is no problem even if the difference is about 0%.
そして、上記■としては、上記■を通常の焼成法にした
がって仮焼することによって得られる低臨界温度相の酸
化物超電導焼結体やそれを粉砕した粉末、さらにはこの
酸化物超電導体粉末を用いて溶融凝固させた溶融凝固体
、溶融後の冷却速度を充分に遅くすることによって得ら
れる単結晶体などが用いられる。As for the above (■), the oxide superconducting sintered body in the low critical temperature phase obtained by calcining the above (2) according to a normal calcination method, the powder obtained by crushing it, and furthermore, the oxide superconducting powder is used. A molten solidified body obtained by melting and solidifying a solidified body using a molten metal, a single crystal body obtained by sufficiently slowing down the cooling rate after melting, etc. are used.
また、上記■は上記■の混合粉末からＣａの配合量を減
らしたもの、あるいはＣａを除いて混合したものであり
、上記■はこの■の混合粉末を仮焼することによって得
られる酸化物の焼結体やそれを粉砕した粉末である。In addition, the above ■ is a mixture of the mixed powder of the above ■ with a reduced amount of Ca, or a mixture without Ca, and the above ■ is an oxide obtained by calcining the mixed powder of the above ■. It is a sintered body or a powder obtained by crushing it.
第１の発明における他方の出発原料となる（Ｂ）成分と
しては、Ｃａ２ ＰｂＯ４あるいはＣａ２ Ｐｂ０４と
ＣｕＯの混合物が用いられる。Ｃａ２ ＰｂＯ４は、た
とえばＣａＣ０３とＰｂＯとを所定のモル比で混合し、
焼成することによって得られ、このＣａ２ ＰｂＯ４は
熱処理時においても安定した状態を保ち、高臨界温度相
生成温度においてＰｂによるＢｉの置換を促進するとと
もに、ＣａＯ倶給源として安定して作用する。As the component (B) which is the other starting material in the first invention, Ca2PbO4 or a mixture of Ca2Pb04 and CuO is used. Ca2PbO4 is produced by mixing CaC03 and PbO at a predetermined molar ratio, for example.
Obtained by calcination, this Ca2PbO4 remains stable even during heat treatment, promotes the substitution of Bi by Pb at the high critical temperature phase formation temperature, and stably acts as a CaO source.
第２の発明における一方の出発原料となる（Ｃ）成分と
しては、上述した第１の発明における（Ａ）成分のうち
、予め結晶化した上記■の低臨界温度相を主とするＢｉ
−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体の焼結体やそ
の粉末、あるいは溶融凝固体や単結晶体が用いられる。As the component (C) which is one of the starting materials in the second invention, among the components (A) in the first invention described above, Bi which is pre-crystallized and mainly has the low critical temperature phase of
A sintered body of a -8r-Ca-Cu-0 based oxide superconductor, a powder thereof, a molten solidified body, or a single crystal body is used.
また、他方の出発原料である（Ｄ）成分としては、Ｃａ
の酸化物（熱処理時において酸化物に転化する化合物を
含む。）とＰｂの酸化物との混合物、あるいはこれにＣ
ｕの酸化物をさらに混合したものが用いられ、Ｃａの酸
化物とＰｂの酸化物とは熱処理過程においてＣａ２ Ｐ
ｂｏ ４を形成し、ＰｂによるＢｉの置換を促進゛し、
高臨界温度相の生成率を高める。In addition, as the other starting material (D) component, Ca
(including compounds that convert into oxides during heat treatment) and an oxide of Pb, or a mixture of Pb oxide and C
A mixture of oxide of u is used, and the oxide of Ca and the oxide of Pb are converted to Ca2P
form bo 4 and promote the substitution of Bi by Pb,
Increase the production rate of high critical temperature phase.
第１の発明における（Ａ）成分と（Ｂ）成分との熱処理
時における存在形態としては、たとえば以下に示すよう
な形態が例示される。Examples of the forms in which the components (A) and (B) exist during the heat treatment in the first invention include the forms shown below.
（ａ） （Ａ）成分および（Ｂ）成分それぞれを粉末
として使用する際には、所定の比率で混合し、たとえば
プレス成形などによって成形体を形成する。(a) When using the components (A) and (B) as powders, they are mixed in a predetermined ratio and formed into a molded body by, for example, press molding.
（ｂ） 焼結体、溶融凝固体、単結晶などのバルク状
の（Ａ）成分を、粉末状の（Ｂ）成分中に埋設する。(b) A bulk component (A) such as a sintered body, a molten solidified body, or a single crystal is embedded in a powdered component (B).
（Ｃ） 焼結体、溶融凝固体、単結晶などのバルク状
の（Ａ）成分の表面に、（Ｂ）成分を溶剤に溶かしたも
のを塗布したり、あるいはスパッタ法や蒸着法などを使
用し、（Ａ）成分の表面に（Ｂ）成分の層を形成して（
Ａ）成分と（Ｂ）成分とを充分に接触させる。(C) Applying a solution of component (B) in a solvent to the surface of component (A) in bulk, such as a sintered body, molten solidified body, or single crystal, or using sputtering or vapor deposition. Then, by forming a layer of component (B) on the surface of component (A),
Component A) and component (B) are brought into sufficient contact.
なお、（Ａ）成分としては、上述した■〜■のいずれの
ものでも使用可能であるが、予め結晶化して低臨界温度
相を主とする酸化物超電導体としたもの（■）を使用す
ることにより、特に本発明の効果が顕著に現れ好ましい
。In addition, as component (A), any of the above-mentioned items from ■ to ■ can be used, but one that has been crystallized in advance to form an oxide superconductor mainly having a low critical temperature phase (■) is used. This is particularly preferable because the effects of the present invention are particularly noticeable.
また、第２の発明における（Ｃ）成分と（Ｄ）成分につ
いても、上記（ａ）〜（Ｃ）のいずれの形態を用いても
よいが、特に上記（ｂ）および（Ｃ）と同様に、バルク
状の（Ｃ）成分を用いることが好ましい。Also, for the (C) component and (D) component in the second invention, any of the forms (a) to (C) above may be used, but in particular, similar to the above (b) and (C), , it is preferable to use bulk component (C).
なお、（Ａ）成分および（Ｃ）成分は、上述したような
バルクとして用いる以外に、線材化したものや薄膜など
の各種形態のものを用いることが可能である。In addition to using the component (A) and the component (C) in the bulk form as described above, it is possible to use various forms such as a wire rod or a thin film.
上記（ａ）の形態を使用する際の（Ａ）成分と（Ｂ）成
分、あるいは（Ｃ）成分と（Ｄ）成分の混合比は、基本
的に得られる熱処理体の組成比がＰｂを含有するＢｉ−
８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体の高臨界温度相
である、
化学式： （Ｂｉ．Ｐｂ）２Ｓｒ＋ Ｃａ２ＣＬＩ３
０Ｘ ・＝ （ｍ）となるように混合することが好
ましいが、必ずしもこれに限定されるものではなく、た
とえばＳ「やＣａは上記（ｍ）式の原子比から±ｌＯ％
程度ずれていても高臨界温度相として作用する。また、
（Ａ）成分および（Ｃ）成分にＰｂおよび高臨界温度相
に対して不足しているＣａおよびＣｕを供給しうる程度
の、混合比であっても、高臨界温度相の生成率を高める
ことができる。When using the form (a) above, the mixing ratio of components (A) and (B) or components (C) and (D) is basically such that the composition ratio of the resulting heat-treated body contains Pb. Bi-
High critical temperature phase of 8r-Ca-Cu-0 based oxide superconductor, chemical formula: (Bi.Pb)2Sr+ Ca2CLI3
It is preferable to mix so that 0X ・= (m), but it is not necessarily limited to this. For example, S' and Ca are mixed by ±lO% from the atomic ratio of formula (m) above.
Even if the degree is different, it acts as a high critical temperature phase. Also,
To increase the production rate of the high critical temperature phase even if the mixing ratio is such that the (A) and (C) components can be supplied with Pb and Ca and Cu that are insufficient for the high critical temperature phase. Can be done.
また、上記（ｂ）および（Ｃ）の形態を使用する際には
、（Ｂ）成分および（Ｄ）成分の層中から（Ａ）成分お
よび（Ｃ）成分にＰｂおよび不足しているＣａおよびＣ
ｕを充分に供給できるように、接触面積および（Ａ）成
分および（Ｃ）成分の体積を考慮する。In addition, when using the above embodiments (b) and (C), Pb and insufficient Ca and C
The contact area and the volumes of component (A) and component (C) are considered so that u can be sufficiently supplied.
そして、上述したような各形態により（Ａ）成分と（Ｂ
）成分、および（Ｃ）成分と（Ｄ）成分とを混合または
接触させて熱処理を施す。Then, the (A) component and (B
), and the components (C) and (D) are mixed or brought into contact and subjected to heat treatment.
この熱処理は、８００℃〜９００℃の範囲で行うことが
好ましい。熱処理温度が８００℃未満では、（Ａ）成分
と（Ｂ）成分、および（Ｃ）成分と（Ｄ）成分との反応
が充分に進まず、高臨界温度相が充分に生成しない。ま
た、９００℃を超えると生成した高臨界温度相が分解し
てしまう。This heat treatment is preferably performed at a temperature of 800°C to 900°C. If the heat treatment temperature is less than 800°C, the reactions between components (A) and (B) and between components (C) and (D) will not proceed sufficiently, and a high critical temperature phase will not be sufficiently generated. Furthermore, if the temperature exceeds 900°C, the generated high critical temperature phase will decompose.
また、この熱処理時の酸素分圧は、たとえば１／１００
〜１Ｏａｔａ＋というように、各種の条件下で行うこと
が可能である。Further, the oxygen partial pressure during this heat treatment is, for example, 1/100
It is possible to carry out under various conditions such as ~1 Oata+.
（作 用）
第１の発明においては、Ｐｂの供給源として熱処理時に
おいて安定なＣａ２ ＰｂＯ４を用いているため、低臨
界温度相を主とする酸化物超電導体あるいはこれからＣ
ａの含有量を減じた酸化物中のＢｉの一部を充分に組成
制御しつつＰｂで置換することができる。これによって
、Ｃａ２ Ｐｂ０４やＣｕの酸化物がＣａやＣｕの供給
源となって、低臨界温度相を高臨界温度相に効率よくか
つ充分に組成制御しつつ変換することができる。この第
１の発明においては、Ｐｂの供給源としてＣａ２ Ｐｂ
Ｏ４を用いているため、酸化物超電導体側の出発原料と
して、予め結晶化した低臨界温度相を主とする酸化物超
電導体やこれからＣａの含有量を減じた酸化物以外に、
それらの原料粉末を用いても、熱処理時においてＢｌの
一部をＰｂで置換しつつ酸化物超電導体を結晶化するこ
とができるため、高臨界温度相の生成率が充分に高まる
。(Function) In the first invention, since Ca2PbO4, which is stable during heat treatment, is used as a Pb source, it is possible to use an oxide superconductor mainly having a low critical temperature phase or a C
A part of Bi in the oxide with a reduced content of a can be replaced with Pb while sufficiently controlling the composition. Thereby, the oxides of Ca2Pb04 and Cu become sources of Ca and Cu, and the low critical temperature phase can be converted into the high critical temperature phase efficiently and with sufficient composition control. In this first invention, Ca2Pb is used as a Pb supply source.
Since O4 is used, as a starting material for the oxide superconductor side, in addition to pre-crystallized oxide superconductors mainly consisting of a low critical temperature phase and oxides with a reduced Ca content,
Even if these raw material powders are used, the oxide superconductor can be crystallized while replacing a portion of Bl with Pb during heat treatment, so the production rate of the high critical temperature phase can be sufficiently increased.
また、第２の発明においては、酸化物超電導体側の出発
原料として予め結晶化した低臨界温度相を主とする酸化
物超電導体を用い、かつ他方の出発原料とし−てＰｂの
酸化物とＣａの酸化物との混合物を用いているので、Ｐ
ｂの酸化物とＣａの酸化物とが熱処理過程において充分
に反応してＣａ２ ＰｂＯ４が生成し、このＣａ２ Ｐ
ｂＯ４がＰｂおよびＣａの供給源となって、高臨界温度
相を効率よくかつ充分に組成制御して形成することがで
きる。Further, in the second invention, an oxide superconductor mainly consisting of a pre-crystallized low critical temperature phase is used as the starting material for the oxide superconductor side, and an oxide of Pb and Ca are used as the other starting material. Since a mixture of P and oxide is used,
The oxide of b and the oxide of Ca react sufficiently during the heat treatment process to generate Ca2PbO4, and this Ca2P
bO4 serves as a source of Pb and Ca, and a high critical temperature phase can be formed efficiently and with sufficient composition control.
（実施例） 次に、本発明の実施例について説明する。(Example) Next, examples of the present invention will be described.
実施例ｌ
Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体の出発原
料としてＢｉ ２０３ 、ＳｒＣＯ３、ＣａＣＯ３、Ｃ
ｕＯの各粉末をモル比で１：２：２：４または１：３：
１：４となるように所定量計量し、これを充分に混合し
た後、この混合粉末を空気中において８５０℃Ｘ５０時
間の条件で焼成して結晶化させ、Ｂｉ−Ｓｒ−Ｃａ−Ｃ
ｕ−０系酸化物超電導体焼結体を作製した。この焼結体
に対してＸ線回折を行ったところ、低臨界温度相がほと
んどであった。Example 1 Bi203, SrCO3, CaCO3, C as starting materials for Bi-8r-Ca-Cu-0 based oxide superconductor
The molar ratio of each powder of uO is 1:2:2:4 or 1:3:
After weighing a predetermined amount so that the ratio is 1:4 and thoroughly mixing it, this mixed powder is fired in the air at 850°C for 50 hours to crystallize Bi-Sr-Ca-C.
A u-0 based oxide superconductor sintered body was produced. When this sintered body was subjected to X-ray diffraction, it was found that most of the sintered body contained a low critical temperature phase.
次いで、ＣａＣ０３とＰｂＯとをモル比で２＝１となる
ように所定量計量し、これを充分に混合した後、この混
合粉末を空気中において７（１０’ｃ Ｘ １２時間の
条件で焼成して結晶化させ、Ｃａ−Ｐｂ−０系の酸化物
焼結体を作製した。この焼結体についてもＸ線回折を行
ったところ、Ｃａ２ ＰｂＯ４がほとんどであった。Next, predetermined amounts of CaC03 and PbO were weighed so that the molar ratio was 2=1, and after thoroughly mixing them, this mixed powder was fired in the air under the conditions of 7 (10'c x 12 hours). A Ca--Pb-0-based oxide sintered body was produced by crystallization. When this sintered body was also subjected to X-ray diffraction, it was found that most of the sintered body was composed of Ca2PbO4.
次に、上記Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導
体焼結体を粉砕して得た低臨界温度相を主とする酸化物
超電導体粉末と、上記Ｃａ−Ｐｂ−０系の酸化物焼結体
を粉砕して得たＣａ２ Ｐｂｏ ４を主とする酸化物粉
末と、ＣｕＯ粉末とをモル比でｌ：１：ｌとなるように
所定世評量し、これを充分に混合し、この混合粉末をペ
レット状にプレス成形した後、この成形体に対して空気
中において８５０℃×１２時間の条件で熱処理を施して
焼成した。Next, oxide superconductor powder mainly containing a low critical temperature phase obtained by pulverizing the Bi-8r-Ca-Cu-0-based oxide superconductor sintered body and the Ca-Pb-0-based oxide superconductor powder The oxide powder mainly composed of Ca2Pbo4 obtained by crushing the oxide sintered body and the CuO powder were weighed in a predetermined amount so that the molar ratio was 1:1:1, and these were thoroughly mixed. After this mixed powder was press-molded into a pellet shape, the molded body was heat-treated and fired in air at 850° C. for 12 hours.
このようにして得たＢｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化
物超電導体焼結体についてＸ線回折を施したところ、第
１図（ａ）に示すように、高臨界温度相が多量に生成さ
れ、低臨界温度相は大幅に減少していることを確認した
。なお、第１図（ｂ）はＣａ２ Ｐｂ０４を主とする酸
化物粉末とＣｕＯ粉末とともに焼成する以前の酸化物超
電導体のＸ線回折結果を示す図であり、第１図（ｃ）は
ＣａＣ０３とＰｂｏとの混合物を焼成して得たＣａ−Ｐ
ｂ−０系の酸化物焼結体のＸ線回折結果を示す図である
。When the Bi-8r-Ca-Cu-0-based oxide superconductor sintered body thus obtained was subjected to X-ray diffraction, a large amount of high critical temperature phase was observed, as shown in Figure 1(a). It was confirmed that the low critical temperature phase produced was significantly reduced. Furthermore, Fig. 1(b) shows the X-ray diffraction results of the oxide superconductor before firing with oxide powder mainly composed of Ca2Pb04 and CuO powder, and Fig. 1(c) shows the results of X-ray diffraction of the oxide superconductor with CaC03 and CuO powder. Ca-P obtained by firing a mixture with Pbo
It is a figure which shows the X-ray diffraction result of a b-0 type|system|group oxide sintered compact.
また、この酸化物超電導体の臨界温度を磁化測定から求
めたところ、第２図に示すように、１０８Ｋからマイス
ナー効果が確認された。Furthermore, when the critical temperature of this oxide superconductor was determined from magnetization measurements, the Meissner effect was confirmed from 108 K, as shown in FIG.
次に、Ｃａ２ ＰｂＯ、を主とする酸化物粉末とＣｕＯ
粉末ととともに熱処理して得たＢｉ−８ｒ−Ｃａ−Ｃｕ
−０系酸化物超電導体焼結体に対して、さらに空気中で
８５０℃Ｘ １０（１時間の条件で熱処理を施した。Next, oxide powder mainly composed of Ca2PbO and CuO
Bi-8r-Ca-Cu obtained by heat treatment with powder
The -0-based oxide superconductor sintered body was further heat-treated in air at 850° C. for 1 hour.
このようにして得たＢｉ−３ｒ−Ｃａ−Ｃｕ−０系酸化
物超電導体に対してＸ線回折を行ったところ、第３図に
示すように、はぼ高臨界温度相単一相の酸化物超電導体
であることを確認した。When X-ray diffraction was performed on the Bi-3r-Ca-Cu-0-based oxide superconductor obtained in this way, as shown in Figure 3, it was found that the oxidation of a single phase with a high critical temperature phase was observed. It was confirmed that it is a physical superconductor.
また、この酸化物超電導体に対して４端子法によって臨
界温度を測定したところ、抵抗零を示す温度’ｔ １０
８にであった。また、７７Ｋ 、 ＯＴの条件下で臨界
電流密度を測定したところ、ｔ０００Ａ／ｃＴＩと良好
な値が得られた。In addition, when the critical temperature of this oxide superconductor was measured using the four-terminal method, the temperature at which resistance was zero was 't 10
It was on 8th. Further, when the critical current density was measured under the conditions of 77K and OT, a good value of t000A/cTI was obtained.
実施例２
Ｂｉ００３ 、ＳｒＣＯ３、ＣａＣＯ３、ＣｕＯの各粉
末をモル比でｌ：２：１：２となるように所定量評ヱし
、これを充分に混合した後、この混合粉末を８００℃×
２４時間の条件で仮焼し、この仮焼物を粉砕した後、９
５０℃で溶融した。この後、室温まで徐冷して相対密度
９０％の緻密質な８ｌ−８ｒ−Ｃａ−Ｃｕ−０系酸化物
超電導体の溶融凝固体を得た。Example 2 A predetermined amount of each powder of Bi003, SrCO3, CaCO3, and CuO was weighed at a molar ratio of 1:2:1:2, and after thoroughly mixing, the mixed powder was heated at 800°C.
After calcining for 24 hours and crushing this calcined product,
It melted at 50°C. Thereafter, it was slowly cooled to room temperature to obtain a molten solidified body of a dense 8l-8r-Ca-Cu-0 based oxide superconductor with a relative density of 90%.
次に、この溶融凝固体を実施例１で作製したＣａ−Ｐｂ
−０系の酸化物焼結体を粉砕して得たＣａ２ ＰｂＯ４
を主とする酸化物粉末とＣｕＯ粉末との混合粉末（モル
比−１＋１ ）中に埋設し、この状態で空気中で８５０
℃Ｘ１２時間の条件で熱処理を施した。Next, this molten solidified body was converted into the Ca-Pb produced in Example 1.
Ca2 PbO4 obtained by crushing -0 series oxide sintered body
It was buried in a mixed powder (molar ratio -1+1) of oxide powder mainly consisting of
Heat treatment was performed at ℃ for 12 hours.
このように熱処理をして得たＢｉ−８ｒ−Ｃａ−Ｃｕ−
０系酸化物超電導体についてもＸ線回折を行ったところ
、高臨界温度相が多量に生成しており、高臨界温度相の
体積占有率が９５％まで向上していた。Bi-8r-Ca-Cu- obtained by heat treatment in this way
When X-ray diffraction was also performed on the 0-type oxide superconductor, it was found that a large amount of high critical temperature phase was generated, and the volume occupancy of the high critical temperature phase had increased to 95%.
実施例３
実施例２で作製したＢｉ−Ｓｒ−Ｃａ＝Ｃｕ−０系酸化
物超電導体の溶融凝固体を、ＣａＣ０３粉末とＰｂＯ粉
末とＣｕＯ粉末との混合粉末（モル比−２：１：１ ）
中に埋設し、空気中で８５０℃×１２時間の条件で熱処
理を施した。Example 3 The molten solidified body of the Bi-Sr-Ca=Cu-0 based oxide superconductor produced in Example 2 was mixed with a mixed powder of CaC03 powder, PbO powder and CuO powder (molar ratio -2:1:1). )
The specimen was buried in the container and heat treated in air at 850° C. for 12 hours.
このように熱処理をして得たＢｉ−３ｒ−Ｃａ−ＣＩ−
０系酸化物超電導体についてもＸ線回折を行ったところ
、高臨界温度相が多量に生成しており、高臨界温度相の
体積占有率が９０％まで向上していた。Bi-3r-Ca-CI- obtained by heat treatment in this way
When X-ray diffraction was also performed on the 0-type oxide superconductor, a large amount of high critical temperature phase was generated, and the volume occupancy of the high critical temperature phase was increased to 90%.
実施例４
Ｂｆｚ ０３．ＳｒＣＯ３ｓ ＣａＣ０１、ＣｕＯの各
粉末をモル比でｌ：２：ｌ：２となるように所定量評ユ
し、これを充分に混合した後、この混合粉末を１３００
℃× １時間の条件で熱処理し、次いで５００℃まで２
℃／分の徐冷し、この後室温まで放冷して１ｍｍＸ２ａ
＋ｍＸ ０．０３ ｍｍの大きさの低臨界温度相のＢｉ
−３ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体の単結晶体を
得た。Example 4 Bfz 03. A predetermined amount of each powder of SrCO3s CaC01 and CuO was weighed at a molar ratio of 1:2:1:2, and after thoroughly mixing, the mixed powder was heated to 1300 molar ratios.
Heat treated at ℃×1 hour, then heated to 500℃ for 2 hours.
Slowly cooled at ℃/min, then left to cool to room temperature to form a 1mm x 2a
Bi in the low critical temperature phase with a size of +mX 0.03 mm
A single crystal of a -3r-Ca-Cu-0 based oxide superconductor was obtained.
次に、このＢｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導
体の単結晶体を実施例２と同様にＣａ２ ＰｂＯ４を主
とする酸化物粉末とＣｕＯ粉末との混合粉末（モル比−
１：ｌ ）中に埋設して同一条件で熱処理を行った。Next, the single crystal of this Bi-8r-Ca-Cu-0-based oxide superconductor was transformed into a mixed powder (molar ratio -
1:l) and heat-treated under the same conditions.
このようにして熱処理を施した単結晶体についてもＸ線
回折を行ったところ、高臨界温度相に変換していた。When X-ray diffraction was performed on the single crystal that had been heat-treated in this way, it was found that it had been converted to a high critical temperature phase.
［発明の効果コ
以上説明したように本発明によれば、Ｂｉの一部を充分
に組成制御しつつＰｂで置換することができ、これによ
って高臨界温度相を効率よく生成することが可能になる
。[Effects of the Invention] As explained above, according to the present invention, it is possible to replace a part of Bi with Pb while fully controlling the composition, thereby making it possible to efficiently generate a high critical temperature phase. Become.
第１図（ａ）は本発明の一実施例の熱処理を施したＢｉ
−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体のＸ線回折結
果を示す図、第１図（ｂ）は熱処理を施す前のＢ ｉ
−Ｓ ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体のＸ線回折
結果を示す図、第１図（ｃ）はＣａＣ０３とＰｂｏとの
焼成物のＸ線回折結果を示す図、第２図は第１図（ａ）
に示したＢｉ−８ｒ−Ｃａ−Ｃｕ−０系酸化物超電導体
の磁化測定の結果を示す図、第３図は第１図（ａ）に示
したＢｉ−Ｓｒ−Ｃａ−Ｃｕ−０系酸化物超電導体にさ
らに本発明の熱処理を施した酸化物超電導体のＸ線回折
結果を示す図である。
出願人 株式会社 東芝
代理人 弁理士 須 山 佐 −
−Ｍ（Ｘｌσ２ｅｍｕ ）FIG. 1(a) shows Bi heat treated according to an embodiment of the present invention.
A diagram showing the X-ray diffraction results of -8r-Ca-Cu-0 based oxide superconductor, Figure 1(b) is B i before heat treatment.
-S A diagram showing the X-ray diffraction results of r-Ca-Cu-0 based oxide superconductor, Figure 1 (c) is a diagram showing the X-ray diffraction results of the fired product of CaC03 and Pbo, and Figure 2 is Figure 1(a)
Figure 3 shows the results of magnetization measurements of the Bi-8r-Ca-Cu-0 based oxide superconductor shown in Figure 1(a). FIG. 3 is a diagram showing the results of X-ray diffraction of an oxide superconductor obtained by further subjecting the oxide superconductor to the heat treatment of the present invention. Applicant Toshiba Corporation Representative Patent Attorney Suyama Sa - -M (Xlσ2emu)
Claims (2)
導体、加熱により前記Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−Ｏ系酸
化物超電導体となる原料粉末、前記酸化物超電導体より
もＣａの含有量が少ない酸化物、加熱により前記酸化物
となる原料粉末から選ばれた少なくとも１種と、（Ｂ）
Ｃａ＿２ＰｂＯ＿４またはＣａ＿２ＰｂＯ＿４とＣｕの
酸化物との混合物とを 混合あるいは接触させ、その状態で熱処理することを特
徴とする酸化物超電導体の製造方法。(1) (A) Bi-Sr-Ca-Cu-O-based oxide superconductor, raw material powder that becomes the Bi-Sr-Ca-Cu-O-based oxide superconductor by heating, and more than the oxide superconductor. (B) at least one selected from oxides with low Ca content and raw material powders that become the oxides upon heating;
A method for producing an oxide superconductor, comprising mixing or contacting Ca_2PbO_4 or a mixture of Ca_2PbO_4 and an oxide of Cu, and heat-treating in that state.
おおよそ２：３：２で含有する酸化物超電導体と、（Ｄ
）Ｃａの酸化物とＰｂの酸化物との混合物またはＣａの
酸化物とＰｂの酸化物とＣｕの酸化物との混合物とを 混合あるいは接触させ、その状態で熱処理することを特
徴とする酸化物超電導体の製造方法。(2) (C) An oxide superconductor containing Bi, (Sr, Ca), and Cu in an atomic ratio of approximately 2:3:2, and (D
) An oxide characterized by mixing or contacting a mixture of a Ca oxide and a Pb oxide or a mixture of a Ca oxide, a Pb oxide, and a Cu oxide, and heat-treating the mixture in that state. Method for manufacturing superconductors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63272459A JPH02120234A (en) | 1988-10-28 | 1988-10-28 | Production of oxide superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63272459A JPH02120234A (en) | 1988-10-28 | 1988-10-28 | Production of oxide superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02120234A true JPH02120234A (en) | 1990-05-08 |
Family
ID=17514208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63272459A Pending JPH02120234A (en) | 1988-10-28 | 1988-10-28 | Production of oxide superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02120234A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5300486A (en) * | 1993-05-27 | 1994-04-05 | The United States Of America As Represented By The United States Department Of Energy | Synthesis of BiPbSrCaCuO superconductor |
| US5324712A (en) * | 1991-08-16 | 1994-06-28 | Gte Laboratories Incorporated | Formation of the high TC 2223 phase in BI-SR-CA-CU-O by seeding |
-
1988
- 1988-10-28 JP JP63272459A patent/JPH02120234A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5324712A (en) * | 1991-08-16 | 1994-06-28 | Gte Laboratories Incorporated | Formation of the high TC 2223 phase in BI-SR-CA-CU-O by seeding |
| US5300486A (en) * | 1993-05-27 | 1994-04-05 | The United States Of America As Represented By The United States Department Of Energy | Synthesis of BiPbSrCaCuO superconductor |
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