JPH03103351A - Preparation of bi-based oxide superconductor and wire thereof - Google Patents
Preparation of bi-based oxide superconductor and wire thereofInfo
- Publication number
- JPH03103351A JPH03103351A JP1235794A JP23579489A JPH03103351A JP H03103351 A JPH03103351 A JP H03103351A JP 1235794 A JP1235794 A JP 1235794A JP 23579489 A JP23579489 A JP 23579489A JP H03103351 A JPH03103351 A JP H03103351A
- Authority
- JP
- Japan
- Prior art keywords
- precursor
- heat treatment
- based oxide
- oxide superconductor
- producing
- 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.)
- Granted
Links
- 239000002887 superconductor Substances 0.000 title claims abstract description 49
- 239000002243 precursor Substances 0.000 claims abstract description 69
- 150000001875 compounds Chemical class 0.000 claims abstract description 18
- -1 nitric acid Chemical class 0.000 claims abstract description 15
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 11
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 11
- 150000005846 sugar alcohols Polymers 0.000 claims abstract description 11
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 10
- 229910052802 copper Inorganic materials 0.000 claims abstract description 9
- 150000007522 mineralic acids Chemical class 0.000 claims abstract description 9
- 238000010438 heat treatment Methods 0.000 claims description 78
- 239000000203 mixture Substances 0.000 claims description 35
- 238000004519 manufacturing process Methods 0.000 claims description 31
- 238000000034 method Methods 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 11
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 10
- 239000002253 acid Substances 0.000 claims description 9
- 239000007795 chemical reaction product Substances 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 5
- 238000003825 pressing Methods 0.000 claims description 4
- 238000011282 treatment Methods 0.000 claims description 4
- 238000005096 rolling process Methods 0.000 claims description 3
- 238000001125 extrusion Methods 0.000 claims description 2
- 230000018044 dehydration Effects 0.000 claims 1
- 238000006297 dehydration reaction Methods 0.000 claims 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 abstract description 18
- 239000002994 raw material Substances 0.000 abstract description 12
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 abstract description 10
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 abstract description 5
- 229910000019 calcium carbonate Inorganic materials 0.000 abstract description 5
- 235000010216 calcium carbonate Nutrition 0.000 abstract description 5
- 229910017604 nitric acid Inorganic materials 0.000 abstract description 5
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 abstract description 4
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 abstract description 4
- 235000002906 tartaric acid Nutrition 0.000 abstract description 4
- 239000011975 tartaric acid Substances 0.000 abstract description 4
- 229910000018 strontium carbonate Inorganic materials 0.000 abstract description 3
- LEDMRZGFZIAGGB-UHFFFAOYSA-L strontium carbonate Chemical compound [Sr+2].[O-]C([O-])=O LEDMRZGFZIAGGB-UHFFFAOYSA-L 0.000 abstract description 2
- 238000006467 substitution reaction Methods 0.000 abstract description 2
- 238000007669 thermal treatment Methods 0.000 abstract 5
- WMWLMWRWZQELOS-UHFFFAOYSA-N bismuth(iii) oxide Chemical compound O=[Bi]O[Bi]=O WMWLMWRWZQELOS-UHFFFAOYSA-N 0.000 abstract 2
- 150000001261 hydroxy acids Chemical class 0.000 abstract 2
- 150000007524 organic acids Chemical class 0.000 abstract 2
- 238000001035 drying Methods 0.000 abstract 1
- 235000005985 organic acids Nutrition 0.000 abstract 1
- 239000000843 powder Substances 0.000 description 16
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 12
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 11
- 239000012071 phase Substances 0.000 description 8
- 238000009792 diffusion process Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 238000002844 melting Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 238000010298 pulverizing process Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 239000002245 particle Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 229920002125 Sokalan® Polymers 0.000 description 4
- 229960004106 citric acid Drugs 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000004584 polyacrylic acid Substances 0.000 description 4
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 3
- 239000012153 distilled water Substances 0.000 description 3
- 229910021645 metal ion Inorganic materials 0.000 description 3
- 238000003746 solid phase reaction Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000013522 chelant Substances 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 150000002500 ions Chemical group 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000005416 organic matter Substances 0.000 description 2
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 2
- 230000005070 ripening Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- YASYEJJMZJALEJ-UHFFFAOYSA-N Citric acid monohydrate Chemical compound O.OC(=O)CC(O)(C(O)=O)CC(O)=O YASYEJJMZJALEJ-UHFFFAOYSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 229960002303 citric acid monohydrate Drugs 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910000657 niobium-tin Inorganic materials 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000010671 solid-state reaction Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical group [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000003325 tomography Methods 0.000 description 1
- 231100000701 toxic element Toxicity 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-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
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、磁気共鳴断層影像装置（ＭＨＩ−ＣＴ）等の
超電導マグネヅト線材、超電導送電等の導電材さらに磁
気シールド材等として有望視され、開発が進められてい
るＢｉ基の高臨界温度酸化物超電導材の製造方法に関す
る．
〈従来の技術〉
最近、常電導状態から超電導状態に遷移する臨界温度Ｔ
ｃが液体窒素の沸ｍ温度を越える値をもつＹ（イットリ
ウム）基、Ｂｉ（ビスマス）基、ＴＩ（タリウム）基等
の酸化物超電導体が発見されている．Ｂｌ基酸化物超電
導体では、Ｂｉ２ Ｓｒ２ ＣａＣｕ２ ０ｘで示され
る組成の相が約８０ＫのＴｃを、また
Ｂｉ２Ｓｒ２Ｃａ２Ｃｕａ Ｏｖで示される＃ｌ戒の相
が約１０５ＫのＴｃをもつ相は、通常混合状態で生成さ
れるが、最近、Ｂｉの一部をＰｂ″′Ｃ置換することに
より１０５Ｋの高いＴｃをもつ相の割合が大きくなるこ
とが知られている．これらの酸化物系超電導体は、′ａ
体ヘリウムで冷却することが必要であった従来のＮｂ−
ＴｉやＮｂ３ Ｓｎ等の金属系超電導体に比較して格段
に有利な冷却条件で使用できることから、実用上極めて
有望な超電導材料として研究開発が進められている．特
にＢｉ基酸化物超電専体はＴＩのように毒性を有する元
素を含まずにＩＯＯＫ以上のＴｃが得られるため注目さ
れている．酸化物超電導体は、機械的性質が極めて脆い
ため、線材の形に加工する手法の一例として次のような
方法が行なわれている．即ち、酸化物超電導体を構成す
る元素を含む複数の原料粉末を仮焼して、不要成分を除
いた後にこの仮焼粉末を成型加工して所望の径の線ある
いは所望の厚さのテープとし、これに熱処理を施して固
相反応によって所望の組成をもつ酸化物超電導体を生成
させ、超電導線材を製造する方法である．（発明が解決
しようとする課題）
しかしながら、従来の製造法では、原料粉末を完全に均
一に混合することが困難なことから、熱処理を施しても
超電導体全体が完全に均一な組成とならない問題があっ
た．特に長尺線材では線材全長にわたり均一な組成の超
電導体を生成することは事実上不可能であった．このた
め不適当な組成で不十分な超電導特性をもつ局部を形成
することとなり、この結果、線材全体の特性が局部の特
性で制限されてしまう問題点があった．また上記の線材
内部に形成されている酸化物超電導体は、粉末を圧縮し
た成型体を固相反応により焼結したもので、その内部に
微細な空孔が多数存在する．このことから、従来の合金
や金属間化合物に比較して緻密性に欠け、実用上重要な
臨界電流密度Ｊｃを高めるのが困難な問題点かあった。Detailed Description of the Invention (Industrial Application Field) The present invention is expected to be used as a superconducting magnetite wire for magnetic resonance tomography (MHI-CT), a conductive material for superconducting power transmission, and a magnetic shielding material. This article relates to a method for producing Bi-based high critical temperature oxide superconducting materials, which are currently being developed. <Prior art> Recently, the critical temperature T at which the normal conductive state transitions to the superconducting state has been
Oxide superconductors such as Y (yttrium), Bi (bismuth), and TI (thallium) groups have been discovered whose c exceeds the boiling temperature of liquid nitrogen. In a Bl-based oxide superconductor, the phase with the composition Bi2 Sr2 CaCu2 0x has a Tc of about 80 K, and the phase with the #l precept shown as Bi2 Sr2 Ca2 Cua Ov has a Tc of about 105 K, usually in a mixed state. However, it has recently been known that replacing a part of Bi with Pb'''C increases the proportion of the phase with a high Tc of 105K.
Conventional Nb-
Since it can be used under much more advantageous cooling conditions than metallic superconductors such as Ti and Nb3Sn, research and development is progressing as an extremely promising superconducting material for practical use. In particular, Bi-based oxide superelectric materials are attracting attention because they do not contain toxic elements like TI and can provide Tc higher than IOOK. Oxide superconductors have extremely fragile mechanical properties, so the following method is used as an example of a method for processing them into wire rods. That is, a plurality of raw material powders containing elements constituting an oxide superconductor are calcined, unnecessary components are removed, and then the calcined powder is molded into a wire of a desired diameter or a tape of a desired thickness. This is a method of manufacturing superconducting wire by subjecting it to heat treatment and producing an oxide superconductor with the desired composition through a solid-state reaction. (Problem to be solved by the invention) However, in conventional manufacturing methods, it is difficult to mix raw material powders completely uniformly, so even if heat treatment is performed, the entire superconductor does not have a completely uniform composition. was there. In particular, with long wires, it is virtually impossible to produce a superconductor with a uniform composition over the entire length of the wire. This results in the formation of localized areas with inadequate superconducting properties due to inappropriate composition, resulting in the problem that the properties of the entire wire are limited by the localized properties. Furthermore, the oxide superconductor formed inside the wire mentioned above is a compacted powder compacted by sintering through a solid phase reaction, and there are many fine pores inside it. For this reason, compared to conventional alloys and intermetallic compounds, it lacks compactness, making it difficult to increase the critical current density Jc, which is important for practical use.
更に、Ｂｉ基酸化物系超電専体では、高Ｔ ｃ相を生成
させるためには、熱処理に数百時間といった長時間を要
する．
本発明は、均一な組成を持つ緻密な酸化物超電導体を得
ることを可能にし、かつ成分元素のｍ量調整や他元素の
添加も極めて簡単に制御でき、さらに短時間の熱処理で
高Ｔｃを得ることができるＢｉ基酸化物Ｂ電導体及びそ
の線材製造方法を提供するものである．
〈課題を解決するための手段〉
かかる目的を達成するため、本発明のＢｉ基酸化物超電
導体の製造方法は、Ｂｉ，Ｓｒ，Ｃａ，Ｃｕを含む化合
物を無機酸に溶解し、蒸溜水で希釈しヒドロキシル酸、
多価アルコールを加えて、加熱撹拌して有機酸塩を生成
させた後、脱水、冷却して得たゲル状の反応生戒物を加
熱分解し、前駆体とした後に熱処理を行うようにしてい
る．また、本発明のＢｉ基酸化物超電導体の製造方法は
、少なくともＳｒ，Ｃａを含む化合物を無機酸に溶解し
、ヒドロキシル酸と多価アルコールを加えて有機酸塩を
生成させたのち脱水して得た反応生成物を加熱分解処理
した前駆体Ａと、少なくともＢｉ．Ｃｕを含む化合物に
同様な処理を行うて生成した前駆体Ｂを混合し、熱処理
を行うようにしている．
ここで、前駆体とはゲル状の有機酸塩を熱分解によって
ゲル中に含まれている水分、残余ガスおよび有機分を除
去した後に得られる灰状の物質を指す．また、無機酸と
しては硝酸、塩酸、硫酸等が挙げられる．また、ヒドロ
キシル酸としては、クエン酸、酒石酸、ポリアクリル酸
等が挙げられ、クエン酸やポリアクリル酸の使用が好ま
しい。そして多価アルコールとしては、２価以上の多価
アルコール、例えばエチレングリコール、ジエチレング
リコール、ポリエチレングリコール、グリセリン、トリ
ヒドロキシベンゼン等が挙げられ、エチレングリコール
またはジエチレングリコールの使用が好ましい．
更に、本発明で製造するＢｉ基酸化物超電導体は、先に
述べたＢｉ２Ｓｒ２ＣａＣ，ｕ２０ｘ、Ｂｉ２ Ｓｒ２
Ｃａ２ Ｃｕ３ ０ｙ及びＢｉ並びに前駆体ＢのＢｉ
の一部をＰｂで置換した組成を含む．更に、本発明のＢ
ｉ基酸化物超電導体の製造方法においては、上述の製法
によって得られた前駆体あるいは前駆体Ａと前駆体Ｂの
混合物に対して、６００℃〜８２０℃の範囲にある一次
熱処理と、この熱処理の後に行う８３０℃〜８７０℃の
範囲にある二次熱処理からなる熱処理を施している．ま
た、本発明のＢｉ基酸化物超電導線材の製造方法は、上
述の一次熱処理の後、その素材を線状物に形成してから
二次熱処理を行うことによって得られる．
（実施例）
以下、本発明の製造方法を実施例に基づいて詳細に説明
する．
原料にはＢ ｉ２０ｓ 、ＳｒＣＯｓ 、ＣａＣＯａ、
ＣｕＯそして必要に応じてＢ−ｉ２０ａと置換するＰｂ
３０４等の原料粉末を所定の組成比に秤量し、硝酸、塩
酸、硫酸等の無ｉ酸に溶解した後、蒸溜水で希釈する。Furthermore, in Bi-based oxide superelectric materials, heat treatment takes a long time, such as several hundred hours, in order to generate a high T c phase. The present invention makes it possible to obtain a dense oxide superconductor with a uniform composition, and it is also possible to extremely easily control the m amount adjustment of component elements and the addition of other elements, and furthermore, a high Tc can be achieved with a short heat treatment. The present invention provides a Bi-based oxide B conductor that can be obtained and a method for manufacturing the wire. <Means for Solving the Problems> In order to achieve the above object, the method for producing a Bi-based oxide superconductor of the present invention includes dissolving a compound containing Bi, Sr, Ca, and Cu in an inorganic acid, and dissolving the compound in distilled water. diluted hydroxyl acid,
After adding a polyhydric alcohol and heating and stirring to generate an organic acid salt, the resulting gel-like reaction product is dehydrated and cooled, which is then thermally decomposed to form a precursor, which is then subjected to heat treatment. There is. In addition, the method for producing a Bi-based oxide superconductor of the present invention includes dissolving a compound containing at least Sr and Ca in an inorganic acid, adding hydroxyl acid and a polyhydric alcohol to form an organic acid salt, and then dehydrating the compound. Precursor A obtained by thermally decomposing the obtained reaction product, and at least Bi. Precursor B produced by subjecting a Cu-containing compound to similar treatment is mixed and heat treated. Here, the precursor refers to an ash-like substance obtained after removing water, residual gas, and organic components contained in the gel by thermal decomposition of the gel-like organic acid salt. In addition, examples of inorganic acids include nitric acid, hydrochloric acid, and sulfuric acid. Further, examples of hydroxyl acids include citric acid, tartaric acid, polyacrylic acid, etc., and use of citric acid and polyacrylic acid is preferred. Examples of the polyhydric alcohol include polyhydric alcohols having a valence of two or more, such as ethylene glycol, diethylene glycol, polyethylene glycol, glycerin, trihydroxybenzene, etc., and it is preferable to use ethylene glycol or diethylene glycol. Furthermore, the Bi-based oxide superconductor produced in the present invention includes the aforementioned Bi2Sr2CaC, u20x, Bi2 Sr2
Ca2 Cu3 Oy and Bi and Bi of precursor B
Contains a composition in which part of is replaced with Pb. Furthermore, B of the present invention
In the method for producing an i-based oxide superconductor, the precursor obtained by the above-mentioned production method or the mixture of precursor A and precursor B is subjected to primary heat treatment in the range of 600°C to 820°C, and this heat treatment. After that, a heat treatment consisting of a secondary heat treatment in the range of 830°C to 870°C is performed. Further, in the method for producing a Bi-based oxide superconducting wire of the present invention, after the above-mentioned primary heat treatment, the material is formed into a linear product and then subjected to a secondary heat treatment. (Examples) Hereinafter, the manufacturing method of the present invention will be explained in detail based on Examples. Raw materials include B i20s, SrCOs, CaCOa,
CuO and optionally Pb replacing B-i20a
A raw material powder such as No. 304 is weighed to a predetermined composition ratio, dissolved in an ionic acid such as nitric acid, hydrochloric acid, sulfuric acid, etc., and then diluted with distilled water.
ここで、無機酸を用いる理由は、Ｂ ｉ２０ｓ 、Ｓｒ
ＣＯａ 、ＣａＣＯ３ 、ＣｕＯ、ＰｂｓＯ４を水に可
溶な金属イオンの形にするためである．そして、所定量
のクエン酸、酒石酸、ボリアクリル酸等のヒドロキシル
酸およびエチレングリコール、ジエチレングリコール等
の多価アルコールを加えた後、約９０℃で加熱撹拌して
有機酸塩を生成させる．ここでヒドロキシル酸は、金属
イオンとヒドロキシル酸との錯体化合物（キレート化合
物）を生成させるために用いる．また、多価アルコール
は、生成した金属イオンとヒドロキシル酸との錯体化合
物（キレート化合物）を高分子状に結合させるために用
いる。この有Ｒ酸塩の含まれた溶液を脱水、冷却しゲル
状の反応生成物を約３５０℃で加熱分解し、前駆体を得
る。ここで加熱分解をすることによって、ゲル中に含ま
れる水分や残余ガスを除去し、さらに有機酸塩の有機物
を分解する．この前駆体を粉砕した後、次熱処理を行い
、更に粉砕、成型した後に二次熱処理を行い超電導体を
得る．
Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−０系の場合、その組成比（原
子比）は、Ｓｒを１としてＢ ｉ ０．５ 〜１．５
、Ｃ ａ０．５ 〜１．５、Ｃ ｕ ０．７ 〜２．０
の範囲にあることが望ましい．ここで上記化合物は酸化
物の形態をとるため、Ｏの含有量は上記の元素の量によ
り理論的に計算される．また、有機酸塩を作製する場合
に用いる無機酸（硝酸、塩酸、硫酸等）、ヒドロキシル
酸（クエン酸、酒石酸、ポリアクリル酸等）及び多価ア
ルコール（エチレングリコール、ジエチレングリコール
等）の添加量も上記の元素の量から総イオン価数を算出
することにより理論的に計算される．
本発明では、組成比がこれら範囲がら外れると良好な超
電導特性を得ることが困難となる．尚、上記化合物にお
いてＢｉの一部を組成比（原子比）０．０５〜０．５の
範囲でＰｂに置換すると優れた超電導特性を得る上に更
に有効である．ここで、前記有機酸塩のゲルを基材テー
プ上に印刷法等の手法で連続的に塗布したり、繊維状の
基材を前記有機酸塩のゲル中に浸漬、通過させて連続的
に被覆する等の方法をとれば、Ｂｉ基超電導体の線材を
作製することができる．
また、前記前駆体の組成を直接目的とする超電導体の組
成とせずに、高融点成分（前駆体Ａ）と低融点成分（前
駆体Ｂ）に分けて生成し、両者を混合して一次熱処理お
よび二次熱処理における両前駆体間の拡散反応により超
電導体を生成させることにより、一層均一で緻密なＢｉ
基酸化物超電導体を得ることができる。この場合、前駆
体Ａと前駆体Ｂの適当な組成の選択が、拡散反応によっ
て超電導体を生成する上に極めて重要な役割を果す．
ここで、前記前駆体ＡはＳｒ，ＣａまたはＳｒ，Ｃａ，
Ｃｕの元素を含み、それらの原子比がＳｒをｌとしてＣ
ａ０．２５ 〜１．０ ， Ｃ ｕ Ｏ 〜１．５の
範囲にあり、また、前駆体ＢはＢｉ，ＣｕまたはＢｉ，
Ｃａ，Ｃｕの元素を含み、それらの原子比がＢｉを１と
してＣ ａｏ 〜１．０ 、Ｃ ｕ ０．２５〜１．５
の範囲内にあることが望ましい．
また、前駆体ＢのＢｉの−・部を、Ｂｉｔに対して０．
１〜０．０５の原子組成比でＰｂに置換すると優れた超
電導特性を得る上に更に有効である．更に、上述の前駆
体Ａと前駆体Ｂの混各をモル比が、前駆体Ａを１として
前駆体Ｂが０．５〜２．０の範囲にすることが優れた超
電導特性を得る上に更に有効である．
この製法によると、低融点成分の前駆体Ｂの融点は７０
０〜７５０℃と低いため、二次熱処理において融体とな
り二次熱処理における速やかな拡散反応により高Ｔｃ超
電導体を生成することができる．前駆体Ａの融点は１０
００℃以上であるため拡散反応は固一液相間の反応とな
る．また、本発明による前駆体が微細であることも前記
拡散反応を速めるのに効果である．
次に、上述のプロセスにおいて得られた前駆体（前駆体
Ａと前駆体Ｂの混合物を含む）Ｂｉ基超電導体を生成さ
せるための熱処理を行う。この熱処理は、低い温度で一
次熱処理を行った後、次に高い温度で二次熱処理を行う
とより性能の良好な材料を提供することができる．
一次熱処理は、前駆体中に残留している残余ガス、水分
、そして有機物を分解し、完全に除去することを目的と
し、一次熱処理温度は６００℃〜８２０℃、好ましくは
６５０℃〜８００℃の範囲にある．尚、この前駆体は非
常に反応性が高いため、一次熱処理はＡｒ気流等の不活
性雰囲気中で実施することが望ましい．また、一次熱処
理は前駆体の融点以下の温度で行うことが望ましい。Here, the reason for using inorganic acids is B i20s , Sr
This is to convert COa, CaCO3, CuO, and PbsO4 into metal ion forms that are soluble in water. Then, after adding a predetermined amount of a hydroxyl acid such as citric acid, tartaric acid, or polyacrylic acid, and a polyhydric alcohol such as ethylene glycol or diethylene glycol, the mixture is heated and stirred at about 90°C to produce an organic acid salt. Here, hydroxyl acid is used to generate a complex compound (chelate compound) of metal ions and hydroxyl acid. Further, the polyhydric alcohol is used to bind the generated complex compound (chelate compound) of metal ions and hydroxyl acid into a polymer. The solution containing the R-containing salt is dehydrated and cooled, and the gel-like reaction product is thermally decomposed at about 350° C. to obtain a precursor. By thermally decomposing the gel, water and residual gas contained in the gel are removed, and the organic substances in the organic acid salt are further decomposed. After pulverizing this precursor, a second heat treatment is performed, and after further pulverization and molding, a second heat treatment is performed to obtain a superconductor. In the case of Bi-Sr-Ca-Cu-0 system, its composition ratio (atomic ratio) is B i 0.5 to 1.5 with Sr being 1.
, Ca0.5 ~ 1.5, Cu 0.7 ~ 2.0
It is desirable that the value be within the range of . Here, since the above compound takes the form of an oxide, the content of O is calculated theoretically from the amount of the above elements. Additionally, the amounts of inorganic acids (nitric acid, hydrochloric acid, sulfuric acid, etc.), hydroxyl acids (citric acid, tartaric acid, polyacrylic acid, etc.) and polyhydric alcohols (ethylene glycol, diethylene glycol, etc.) used when producing organic acid salts are also determined. It is calculated theoretically by calculating the total ion valence from the amounts of the above elements. In the present invention, if the composition ratio falls outside of these ranges, it becomes difficult to obtain good superconducting properties. In the above compound, it is more effective to replace a part of Bi with Pb in a composition ratio (atomic ratio) of 0.05 to 0.5 in order to obtain excellent superconducting properties. Here, the gel of the organic acid salt is continuously applied onto the base tape by a method such as printing, or the fibrous base material is immersed and passed through the gel of the organic acid salt. If a method such as coating is used, a wire of Bi-based superconductor can be produced. In addition, instead of making the composition of the precursor directly into the composition of the target superconductor, it is possible to separate the composition into a high melting point component (precursor A) and a low melting point component (precursor B), and then mix the two and perform the primary heat treatment. By producing a superconductor through a diffusion reaction between both precursors during secondary heat treatment, more uniform and dense Bi
A base oxide superconductor can be obtained. In this case, the selection of appropriate compositions of precursor A and precursor B plays a very important role in producing superconductors by diffusion reactions. Here, the precursor A is Sr, Ca or Sr, Ca,
Contains the element Cu, and their atomic ratio is C with Sr as l
a0.25 to 1.0, CuO to 1.5, and the precursor B is Bi, Cu or Bi,
Contains the elements Ca and Cu, and their atomic ratio is Cao ~ 1.0, Cu 0.25 ~ 1.5, with Bi being 1.
It is desirable that the value be within the range of . Further, the -. part of Bi in the precursor B was set to 0.
Substitution with Pb at an atomic composition ratio of 1 to 0.05 is more effective in obtaining excellent superconducting properties. Furthermore, in order to obtain excellent superconducting properties, the molar ratio of the mixture of precursor A and precursor B is in the range of 1 for precursor A and 0.5 to 2.0 for precursor B. It is even more effective. According to this manufacturing method, the melting point of precursor B, which is a low melting point component, is 70.
Since it is as low as 0 to 750°C, it becomes a melt in the secondary heat treatment, and a high Tc superconductor can be produced by a rapid diffusion reaction in the secondary heat treatment. The melting point of precursor A is 10
Since the temperature is above 00°C, the diffusion reaction is a reaction between solid and liquid phases. Furthermore, the fact that the precursor according to the present invention is fine is also effective in accelerating the diffusion reaction. Next, the precursor obtained in the above process (including a mixture of Precursor A and Precursor B) is subjected to heat treatment to produce a Bi-based superconductor. This heat treatment can provide a material with better performance by performing primary heat treatment at a low temperature and then performing secondary heat treatment at a higher temperature. The purpose of the primary heat treatment is to decompose and completely remove residual gas, moisture, and organic matter remaining in the precursor, and the primary heat treatment temperature is 600°C to 820°C, preferably 650°C to 800°C. It is within the range. Since this precursor is highly reactive, it is desirable that the primary heat treatment be carried out in an inert atmosphere such as an Ar stream. Further, it is desirable that the primary heat treatment be performed at a temperature below the melting point of the precursor.
次に、二次熱処理温度は８３０℃〜８７０℃、好ましく
は８４５℃〜８６５℃の範囲でＢｉ基高臨界温度超電導
体の生成温度付近にあり、高い′ｒＣをもつ結晶構造を
形成させる．一次熱処理を省略しても超電桿相を生成さ
せることが可能であるが、前駆体中に残留している残余
ガスや分解された有機物により炭酸ガスや水分が発生す
ることにより試料が急激に膨張あるいは収縮したり、多
孔質になったりし、クラックが発生ずることがある。Next, the secondary heat treatment temperature is in the range of 830° C. to 870° C., preferably 845° C. to 865° C., which is near the formation temperature of the Bi-based high critical temperature superconductor, and forms a crystal structure with a high rC. Although it is possible to generate a superconductor phase even if the primary heat treatment is omitted, the sample may rapidly deteriorate due to the generation of carbon dioxide gas and moisture due to the residual gas remaining in the precursor and the decomposed organic matter. It may expand or contract, become porous, and cracks may occur.
したがって、一次熱処理を省略する場合には、二次熱処
理の際の昇温を４００℃以上の温度域において４００℃
未満のそれよりも遅く、好ましくは１゜Ｃ／分より遅く
行い、残余ガス等を除く必要がある．また、この二次熱
処理を約４００℃で一旦昇温を停止させ、残余ガス等を
除いた後再び昇温するようにしても良い．この場合の昇
温速度は上述の如く遅くする必要はない．
更に、上述の二次熱処理を複数回に分けて実施し、先の
二次熱処理によって試料に超電導特性を持たせた後に更
にプレス、圧延、押出し等の加工工程を加え、再び二次
熱処理を行うと超電導特性の向上を図ることができる．
また、本発明を超電導体の線材化に利用する別の態様と
して、一次熟処理後の素材を長尺線に加工した後、二次
熱処理を行うと高Ｔｃの８１基酸化物超電導線材を作製
することができる．一次熱処理後の素材は、Ａｇ等の金
属シースに充填して加工したり、あるいは金属板の間に
挾んで加工したり、基板テープ上に線状に形成して加工
する．更に、前駆体Ａと前駆体Ｂの間の拡散反応によっ
てＢｉ基酸化物超電導体を生成させると、一層均一で緻
密な組織を得ることができ、超電導特性を向上させるこ
とができる．
実施例Ｉ
Ｂ ｉ２ Ｃ）３ 、ＳｒＣ０３ 、ＣａＣＯ３ 、Ｃ
ｕＯ、原料粉末をＢｉ２ Ｓｒ２ Ｃａ２ Ｃｕ３ ０
Ｙの組成比とるように秤量し、これに蒸溜水を加え、濃
硝酸を加えて溶解し規定量のクエン酸一水和物とエチレ
ングリコールを加えた後ホットプレートスターラー上で
加熱撹拌した。反応が開始すると、液の色は青澄色とな
り、反応が進行するにつれて白色のｒｌ１，ｍな沈澱が
生成し、ＮＯｘの発生と共に水分の蒸発が起こり、液量
が減少した．反応が終了すると、試料は粘性を帯びたゾ
ルとなり、ＮＯｘの発生によりスポンジ状に膨れ上がっ
た．これを冷却すると固化し、ゲルとなった．このゲル
を電気炉において３５０℃で１．５時間熱分解し、前駆
体を得た．この前駆体を粉砕し、一次熱処理として７８
０”Ｃで８時間熱処理の後、粉砕を繰返し行った．粉砕
した前駆体の粒度分布を第１図に示す．前駆体は、ほぼ
粒径１０＋．ｏｎ以下の微細な粒子からなっている．こ
の粉末を２ ｔｏｎの荷重でプレスして幅４間、長さ３
０間、厚さ約１間のテープ状に戒型し、８６０℃で２０
時間二次熱処理を施した．尚、本実施例の熱処理はいず
れも大気中で行った．この試料のＴｃを直流４端子法に
より測定したところ６０Ｋのゼロ抵抗温度が得られた．
Ｘ腹透ユ
Ｂ ｉ２０ａ 、ＳｒＣＯｓ 、ＣａＣＯａ 、Ｃｕｂ
，Ｐｂ３ｏ４の原料粉末を
Ｂ ｉ ＋．ｓ Ｐｂｏ２Ｓｒ２ Ｃａ２Ｃｕ，Ｏｖの
組成比となるように秤量し、実施例１と同様な方法で前
駆体を作製した．この前駆体を粉砕し、一次熱処理とし
て７８０℃で８時間熱処理の後、粉砕を繰返し行った．
この粉末を２ ｔｏｎの荷重でプレスして幅４ＬｗｗＩ
、長さ３０ｗ、厚さ約１ｆｆｌＩＩのテープ状に成型し
、８４５℃〜８６５゜Ｃで２０時間二次熱処理を施した
．尚、本実施例の熱処理はいずれも大気中で行った．８
５５℃以上の温度で熱処理を施した場合に液体窒素温度
（−１９６℃＝７７Ｋ）以上で超電導性を示すことが直
流４端子法による測定の結果判明した．特に８６０℃の
場合、試料のゼロ抵抗温度は約１０２Ｋであった。Therefore, if the primary heat treatment is omitted, the temperature during the secondary heat treatment should be increased to 400°C in the temperature range of 400°C or higher.
It is necessary to remove residual gas etc. at a slower rate than that of less than 1°C/min, preferably slower than 1°C/min. Alternatively, the secondary heat treatment may be performed by temporarily stopping the temperature rise at about 400°C, and after removing residual gas, etc., the temperature may be raised again. In this case, the heating rate does not need to be as slow as described above. Furthermore, the above-mentioned secondary heat treatment is performed in multiple steps, and after the sample is given superconducting properties by the previous secondary heat treatment, further processing steps such as pressing, rolling, and extrusion are added, and the secondary heat treatment is performed again. It is possible to improve the superconducting properties. In addition, as another aspect of utilizing the present invention for making superconductor wires, a high Tc 81-group oxide superconducting wire can be produced by processing the material after the primary ripening treatment into a long wire and then performing a secondary heat treatment. can do. After the primary heat treatment, the material is processed by filling it into a metal sheath such as Ag, by sandwiching it between metal plates, or by forming it into a line on a substrate tape. Furthermore, if a Bi-based oxide superconductor is produced by a diffusion reaction between precursor A and precursor B, a more uniform and dense structure can be obtained, and the superconducting properties can be improved. Example I B i2 C)3 , SrC03 , CaCO3 , C
uO, raw material powder Bi2 Sr2 Ca2 Cu3 0
The mixture was weighed to maintain the composition ratio of Y, and distilled water was added thereto. Concentrated nitric acid was added to dissolve the mixture. After adding specified amounts of citric acid monohydrate and ethylene glycol, the mixture was heated and stirred on a hot plate stirrer. When the reaction started, the color of the liquid became clear blue, and as the reaction proceeded, a white precipitate was formed, NOx was generated, water evaporated, and the liquid volume decreased. When the reaction was completed, the sample became a viscous sol, which swelled into a spongy shape due to the generation of NOx. When this was cooled, it solidified and became a gel. This gel was thermally decomposed in an electric furnace at 350°C for 1.5 hours to obtain a precursor. This precursor is pulverized and subjected to primary heat treatment at 78°C.
After heat treatment at 0''C for 8 hours, pulverization was repeated. The particle size distribution of the pulverized precursor is shown in Figure 1. The precursor consists of fine particles with a particle size of approximately 10+.on or less. Press this powder with a load of 2 tons to make a width of 4 and a length of 3.
It was molded into a tape with a thickness of about 1 mm and heated at 860℃ for 20 minutes.
Secondary heat treatment was performed. Note that all heat treatments in this example were performed in the atmosphere. When the Tc of this sample was measured using the DC 4-terminal method, a zero resistance temperature of 60K was obtained.
X-hara-toyu B i20a, SrCOs, CaCOa, Cub
, Pb3o4 raw material powder is B i +. A precursor was prepared in the same manner as in Example 1 by weighing so as to have a composition ratio of sPbo2Sr2Ca2Cu,Ov. This precursor was pulverized, and after a primary heat treatment at 780°C for 8 hours, pulverization was repeated.
Press this powder with a load of 2 tons to make a width of 4LwwI.
The tape was formed into a tape having a length of 30W and a thickness of about 1fflII, and was subjected to a secondary heat treatment at 845°C to 865°C for 20 hours. Note that all heat treatments in this example were performed in the atmosphere. 8
Measurements using the DC four-terminal method revealed that when heat-treated at a temperature of 55°C or higher, it exhibits superconductivity above the liquid nitrogen temperature (-196°C = 77K). In particular, at 860°C, the zero resistance temperature of the sample was approximately 102K.
実施例３
実施例２と同様な方法で作製した前駆体を一次熱処理と
して７８０℃で８時間熱処理の後、粉砕を繰返し行った
．この粉末を２ ｔｏｎの荷重でプレスして幅４關、長
さ３０Ｉ１ｆｌ、厚さ約１ ａｍのテープ状に成型し、
８６０℃で２０時間二次熱処理を施した．この試料に３
ｔｏｎの荷重でプレス加工を施して幅４ｌｌｌＩ、長
さ３０間、厚さ約１ ｎｎのテープ状に成型し、８６０
℃で２０時間二次熱処理を施した。尚、本実施例の熱処
理はいずれも大気中で行った．この試料のＴｃを直流４
＠子法により測定したところ約１０５Ｋのゼロ抵抗温度
が得られた．従来の固相反応法では高Ｔｃを得るために
数百時間の熱処理を要するが、この結果より本製造法に
よると熱処理は４０時間に短縮できることが確認された
．
Ｘ旌皿１
Ｂｉ２ ０３ 、ＳｒＣＯ３ 、ＣａＣＯ３ 、ＣｕＯ
、Ｐｂ３ ０４の原料粉末を
Ｂｉ ＋．ａ Ｐｂｏ２Ｓｒ ２Ｃａ＋．ａ Ｃｕｓ
Ｏｙの組成比となるように秤量し、実施例１と同様な方
法で前駆体を作製した。この前駆体を粉砕し、一次熱処
理として７８０℃で８時間熱処理の後、粉砕を繰返し行
った．この粉末を２【Ｏｎの荷重でプレスして幅４間、
長さ３０間、厚さ約１關のテーグ状に成型し、８６５℃
で２０時間二次熱処理を胸した．この試料を再び３【Ｏ
ｎの荷重でプレス加工して８６０゜Ｃで２０時間熱処理
を施した後、更に３ ｔｏｎの荷重でプレス加工して、
８６０℃で２０時間熟処理を施した．尚、本実施例の熱
処理はいずれも大気中で行った．この試料のＴｃを直流
４端子法により測定したところ約１０６Ｋのゼロ抵抗温
度が得られた．第２図にこの遷移曲線を示す．Ｘ腹皿互
ＳｒＣＯａ ，ＣａＣＯａの原料粉末をＳｒ２ Ｃａ２
０４の組戒となるように秤量し、実施例１と同様な方
法で前駆体を作製し、前駆体Ａとした．また、Ｂｉ２
０ａ ，ＣｕＯの原科粉末をＢ ｉ２ Ｃｕ２ ０５の
組成となるように秤量し、実施例ｌと同様な方法で前駆
体を作製し、前駆体Ｂとした．両者を１＝１、３のモル
比でよく混合し、一次熱処理を７００℃で１０時間行っ
た後、粉砕を繰返して行った．
この混合粉末を内径５ＩＩＩＩｌ、外径８間、長さ８０
闘のＡｇ管に充填して栓をし、清ロールによって２．５
１ＷＩＩ角の棒状に加工した後、平ロールにより熱さ１
＋ｎ＋、幅５ ｍｍのテープに圧延した．ここで、８
６０℃で１０時間の二次熱処理を行った後、厚さ０．３
＋ｍまで圧延して、再び８６０℃で１０時間の熱処理を
行った。尚、本実施例の熱処理はいずれも大気中で行っ
た．
この試料のＴｃを直流４端子法により測定したところ７
３Ｋのゼロ抵抗温度が得られた．また、その臨界電流密
度Ｊｃを測定したところ４．２ＫでＩＴの磁界下で実施
例１の試料に比べて約１５倍の高い値が得られた．
哀亘班亙
ＳｒＣＯｓ ．ＣａＣＯａ ，ＣｕＯの原料粉末をＳｒ
２ ＣａＣｕ２０ｓの組成となるように秤量し、実施例
■と同様な方法で前駆体を作製し、前駆体Ａとした．ま
た、Ｂｉ２ ０ｓ ，Ｐｂ３０４ ，ＣａＣＯ３ ，Ｃ
ｕＯの原料粉末を
Ｂ ｉ ｒ．ａ Ｐ ｂ ０．２Ｃ ａＣ ｕ ＋．ｓ
Ｏｓ．ｓの組成となるように秤量し、実施例１と同様
な方法で前駆体を作製し、前駆体Ｂとした．両者を１＝
１のモル比でよく混合し、一次熱処理を６５０゜Ｃで１
０時間行った後、粉砕を繰返して行った．
この混合粉末を内径５叩、外径８１ｌＩＩ、長さ８０間
のＡｇ管に充填して栓をし、清ロールによって２，５間
角の棒状に加工した後、平ロールにより熱さＩＩＩＩＩ
ｌ、幅５曲のテープに圧延した．ここで、８５５℃で１
０時間の二次熱処理を行った後、厚さ０．３ａ＋ｎまで
圧延して、再び−８５５℃で１０時間の二次熱処理を行
った．尚、本実施ρＩの熱処理はいずれも大気中で行っ
た．
この試料のＴｃを直流４端子法により測定したところ１
０７Ｋのゼロ抵抗温度が得られた．また、その臨界電流
密度Ｊｃを測定したところ７７Ｋで実施例２の試料に比
べて約２０倍の高い値が得られた．
（発明の効果）
以上の説明より明らかなように、本発明のＢｉ基酸化物
超電導体の製造方法によると、組成が非常に均一でしか
も緻密なＢｉ基高Ｔｃ酸化物超電導体を作製し得る．特
に本発明は、適当な組成を有する高融点成分の前駆体Ａ
と低融点成分の前駆体Ｂとを生威し、両者を混合して一
次熱処理及び／又は二次熱処理における両前駆体間の拡
散反応により超電導体を生成するようにしているので、
一層均一で緻密なＢｉ基酸化物超電導体を提供すること
ができる．そのため、本製造法を線材作製に適用した場
合に、Ｊｃが大きくしかも長さ方向に特性の均一なＢｉ
基高Ｔｅａ化物超電導体線材を製造することが可能とな
る．また、Ｂｔ基酸化物系超電導体では、高Ｔｃ相を生
或させるためには、熱処理に数百時間といった長時間を
要するが、本製造法では数十時間の熱処理により高Ｔｃ
相か得られることから、熱処理時間を短縮して製造工程
の能率を高めることができる。Example 3 A precursor prepared in the same manner as in Example 2 was first heat treated at 780°C for 8 hours, and then pulverized repeatedly. This powder was pressed with a load of 2 tons and formed into a tape shape with a width of 4 mm, a length of 30 cm, and a thickness of about 1 am.
Secondary heat treatment was performed at 860°C for 20 hours. 3 for this sample
It was pressed under a load of 100 ton and formed into a tape shape with a width of 4 lll I, a length of 30 mm, and a thickness of about 1 nn.
A secondary heat treatment was performed at ℃ for 20 hours. Note that all heat treatments in this example were performed in the atmosphere. Tc of this sample is DC4
When measured using the @ko method, a zero resistance temperature of approximately 105K was obtained. Conventional solid phase reaction methods require several hundred hours of heat treatment to obtain a high Tc, but these results confirm that the heat treatment can be shortened to 40 hours using this production method. X dish 1 Bi2 03 , SrCO3 , CaCO3 , CuO
, Pb3 04 raw material powder is converted into Bi + . a Pbo2Sr 2Ca+. a Cus
A precursor was produced in the same manner as in Example 1 by weighing so as to have a composition ratio of Oy. This precursor was pulverized, and after a primary heat treatment at 780°C for 8 hours, pulverization was repeated. This powder was pressed with a load of 2 [On] to a width of 4.
Molded into a tag shape with a length of 30 cm and a thickness of about 1 cm, heated to 865℃
Then, a secondary heat treatment was performed for 20 hours. This sample was again 3[O
After pressing with a load of n and heat treatment at 860°C for 20 hours, further pressing with a load of 3 tons,
A ripening treatment was performed at 860°C for 20 hours. Note that all heat treatments in this example were performed in the atmosphere. When the Tc of this sample was measured using the DC 4-terminal method, a zero resistance temperature of approximately 106K was obtained. Figure 2 shows this transition curve. The raw material powders of SrCOa and CaCOa are mixed with Sr2Ca2
A precursor was prepared in the same manner as in Example 1 and designated as Precursor A. Also, Bi2
0a, CuO raw material powder was weighed so as to have a composition of B i2 Cu2 05, and a precursor was prepared in the same manner as in Example 1, and designated as Precursor B. Both were mixed well at a molar ratio of 1=1,3, and after primary heat treatment was performed at 700°C for 10 hours, pulverization was repeated. This mixed powder has an inner diameter of 5IIIl, an outer diameter of 8mm, and a length of 80mm.
Fill and stopper the Ag tube, and use a clean roll to remove 2.5
After processing it into a 1WII square rod shape, it is heated to 1W by a flat roll.
+n+, rolled into a tape with a width of 5 mm. Here, 8
After secondary heat treatment at 60℃ for 10 hours, the thickness is 0.3
After rolling to +m, heat treatment was performed again at 860° C. for 10 hours. Note that all heat treatments in this example were performed in the atmosphere. The Tc of this sample was measured using the DC 4-terminal method and was found to be 7
A zero resistance temperature of 3K was obtained. Furthermore, when the critical current density Jc was measured at 4.2K under the IT magnetic field, a value approximately 15 times higher than that of the sample of Example 1 was obtained. Ai Wataru SrCOs. Raw material powders of CaCOa and CuO are
2 CaCu20s was weighed, and a precursor was prepared in the same manner as in Example ①, which was designated as Precursor A. Also, Bi2 0s , Pb304 , CaCO3 , C
The raw material powder of uO was heated to B i r. a P b 0.2C aC u +. s
Os. A precursor was prepared in the same manner as in Example 1 and designated as Precursor B. Both = 1
Mix well at a molar ratio of 1:1 and perform primary heat treatment at 650°C.
After 0 hours, pulverization was repeated. This mixed powder was filled into an Ag tube with an inner diameter of 5 mm, an outer diameter of 81 l II, and a length of 80 mm, and the tube was plugged and processed into a rod shape of 2.5 mm square with a clear roll.
l, rolled into a tape of 5 widths. Here, 1 at 855℃
After performing secondary heat treatment for 0 hours, it was rolled to a thickness of 0.3a+n, and secondary heat treatment was performed again at -855°C for 10 hours. Note that all of the heat treatments in this ρI experiment were performed in the atmosphere. The Tc of this sample was measured using the DC 4-terminal method and was 1
A zero resistance temperature of 0.07K was obtained. Furthermore, when the critical current density Jc was measured, a value approximately 20 times higher than that of the sample of Example 2 was obtained at 77K. (Effects of the Invention) As is clear from the above explanation, according to the method for producing a Bi-based oxide superconductor of the present invention, it is possible to produce a Bi-based high Tc oxide superconductor that has a very uniform composition and is dense. ．． In particular, the present invention provides a precursor A of a high melting point component having a suitable composition.
and a low-melting-point component precursor B are mixed, and a superconductor is produced by a diffusion reaction between both precursors in the primary heat treatment and/or the secondary heat treatment.
A more uniform and dense Bi-based oxide superconductor can be provided. Therefore, when this manufacturing method is applied to wire rod manufacturing, Bi
It becomes possible to manufacture base height Tea compound superconductor wire. In addition, Bt-based oxide-based superconductors require a long time of heat treatment, such as several hundred hours, to generate a high Tc phase, but with this manufacturing method, a high Tc phase can be achieved by heat treatment for several tens of hours.
Since a phase can be obtained, the heat treatment time can be shortened and the efficiency of the manufacturing process can be increased.
したがって、本製造法は従来の製造法における課題を解
決し、均一性と緻密性が優れたＢｉ基高Ｔｃ酸化物超電
導体を提供することができる。Therefore, this manufacturing method can solve the problems of conventional manufacturing methods and provide a Bi-based high Tc oxide superconductor with excellent uniformity and density.
第１図は本製造法の実施例１により得られた有機酸塩前
駆体の粒度分布を示す図で、縦軸左側に図中の棒グラフ
（ヒストグラム）の粒子径に対する頻度％を表し、縦軸
右閘に図中の曲線の粒子径に対ずるふるい下％を表し、
横軸に粒子径を表す。
第２図は、本製造法の実施例４により得られたＢｉ基酸
化物超電導体試料の電気抵抗の温度変化を示す図で、縦
軸に試料の電気抵抗を表し、横軸に温度を表す。Figure 1 is a diagram showing the particle size distribution of the organic acid salt precursor obtained in Example 1 of the present production method. The right bar shows the percentage under sieve relative to the particle size of the curve in the figure.
The horizontal axis represents the particle size. FIG. 2 is a diagram showing temperature changes in electrical resistance of a Bi-based oxide superconductor sample obtained by Example 4 of the present manufacturing method, with the vertical axis representing the electrical resistance of the sample and the horizontal axis representing temperature. .
Claims (12)
溶解し、ヒドロキシル酸と多価アルコールを加えて有機
酸塩を生成させた後、脱水して得た反応生成物を加熱分
解し、前駆体とした後に熱処理を行うことを特徴とする
Ｂｉ基酸化物超電導体の製造方法。(1) A compound containing Bi, Sr, Ca, and Cu is dissolved in an inorganic acid, hydroxyl acid and polyhydric alcohol are added to produce an organic acid salt, and the reaction product obtained by dehydration is thermally decomposed. . A method for producing a Bi-based oxide superconductor, which comprises performing heat treatment after forming a precursor.
化合物において、その原子比がＳｒを１としてＢｉ０．
５〜１．５、Ｃａ０．５〜１．５、Ｃｕ０．７〜２．０
の範囲内にあることを特徴とする請求項１記載のＢｉ基
酸化物超電導体の製造方法。(2) In a compound composed of the elements Bi, Sr, Ca, and Cu, the atomic ratio is Bi0.
5-1.5, Ca0.5-1.5, Cu0.7-2.0
2. The method for producing a Bi-based oxide superconductor according to claim 1, wherein the Bi-based oxide superconductor is within the range of:
〜０．５の組成原子比でＰｂに置換することを特徴とす
る請求項１又は２記載のＢｉ基酸化物超電導体の製造方
法。(3) Part of Bi in the compound is 0.05 to Bi1
3. The method for producing a Bi-based oxide superconductor according to claim 1 or 2, characterized in that Pb is substituted at a composition atomic ratio of ~0.5.
解し、ヒドロキシル酸と多価アルコールを加えて有機酸
塩を生成させたのち脱水して得た反応生成物を加熱分解
処理した前駆体Ａと、少なくともＢｉ，Ｃｕを含む化合
物に同様な処理を行って生成した前駆体Ｂを混合し、熱
処理を行うことを特徴とするＢｉ基酸化物超電導体の製
造方法。(4) Precursor A obtained by thermally decomposing the reaction product obtained by dissolving a compound containing at least Sr and Ca in an inorganic acid, adding hydroxyl acid and a polyhydric alcohol to produce an organic acid salt, and then dehydrating it. and a precursor B produced by subjecting a compound containing at least Bi and Cu to similar treatment, and heat-treating the mixture.
ｕの元素を含み、それらの原子比がＳｒを１としてＣａ
０．２５〜１．０，Ｃｕ０〜１．５の範囲にあり、また
、前駆体ＢがＢｉ，ＣｕまたはＢｉ，Ｃａ，Ｃｕの元素
を含み、それらの原子比がＢｉを１としてＣａ０〜１．
０、Ｃｕ０．２５〜１．５の範囲内にあることを特徴と
する請求項４記載のＢｉ基酸化物超電導体の製造方法。(5) The precursor A is Sr, Ca or Sr, Ca, C
Contains the elements u, and their atomic ratio is Ca with Sr being 1.
0.25 to 1.0, Cu0 to 1.5, and the precursor B contains Bi, Cu or the elements Bi, Ca, Cu, and the atomic ratio thereof is Ca0 to 1 with Bi being 1. ．．
5. The method for producing a Bi-based oxide superconductor according to claim 4, wherein the Cu content is within a range of 0.0 and Cu0.25 to 1.5.
．０５〜０．５の原子組成比でＰｂに置換することを特
徴とする請求項４又は５記載のＢｉ基酸化物超電導体の
製造方法。(6) A part of Bi of the precursor B is set to 0 with respect to Bi1.
．． 6. The method for producing a Bi-based oxide superconductor according to claim 4, wherein Pb is substituted at an atomic composition ratio of 0.05 to 0.5.
体Ａを１として前駆体Ｂが０．５〜２．０の範囲にある
ことを特徴とする請求項４ないし６のいずれかに記載の
Ｂｉ基酸化物超電導体の製造方法。(7) The molar ratio of the mixture of the precursor A and the precursor B is in the range of 1 for precursor A and 0.5 to 2.0 for precursor B. Any method for producing a Bi-based oxide superconductor.
次熱処理と、この熱処理の後に行う８３０℃〜８７０℃
の範囲にある二次熱処理からなることを特徴とする請求
項１ないし７のいずれかに記載のＢｉ基酸化物超電導体
の製造方法。(8) Primary heat treatment in which the heat treatment is in the range of 600°C to 820°C, and 830°C to 870°C performed after this heat treatment.
8. The method for producing a Bi-based oxide superconductor according to any one of claims 1 to 7, comprising a secondary heat treatment in the range of .
みから成り、４００℃以上に昇温したときに昇温速度を
４００℃未満の場合よりも遅くすることを特徴とする請
求項１ないし７のいずれかに記載のＢｉ基酸化物超電導
体の製造方法。(9) The heat treatment consists of only secondary heat treatment at 830°C to 870°C, and when the temperature is raised to 400°C or higher, the rate of temperature rise is slower than when the temperature is lower than 400°C. 7. The method for producing a Bi-based oxide superconductor according to any one of 7.
のみから成り、約４００℃において一旦昇温を停止する
ことを特徴とする請求項１ないし７のいずれかに記載の
Ｂｉ基酸化物超電導体の製造方法。(10) The Bi-based oxide superconductor according to any one of claims 1 to 7, wherein the heat treatment consists of only a secondary heat treatment at 830°C to 870°C, and the temperature increase is once stopped at about 400°C. How the body is manufactured.
プレス、圧延、押出し等の中間加工処理を施すことを特
徴とする請求項１ないし１０のいずれかに記載のＢｉ基
酸化物超電導体の製造方法。(11) The Bi-based oxide superconductor according to any one of claims 1 to 10, wherein the secondary heat treatment is divided into a plurality of times, and intermediate processing such as pressing, rolling, and extrusion is performed between the steps. How the body is manufactured.
状物に形成し、二次熱処理を行うことを特徴とするＢｉ
基酸化物超電導線材の製造方法。(12) After the primary heat treatment according to claim 8, the material is formed into a linear object and subjected to a secondary heat treatment.
Method for manufacturing base oxide superconducting wire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1235794A JP2966442B2 (en) | 1989-09-13 | 1989-09-13 | Bi-based oxide superconductor and method for producing wire thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1235794A JP2966442B2 (en) | 1989-09-13 | 1989-09-13 | Bi-based oxide superconductor and method for producing wire thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03103351A true JPH03103351A (en) | 1991-04-30 |
| JP2966442B2 JP2966442B2 (en) | 1999-10-25 |
Family
ID=16991361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1235794A Expired - Lifetime JP2966442B2 (en) | 1989-09-13 | 1989-09-13 | Bi-based oxide superconductor and method for producing wire thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2966442B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001302246A (en) * | 2000-04-24 | 2001-10-31 | Murata Mfg Co Ltd | Method of producing ceramic, and ceramic |
| US7008169B1 (en) * | 1999-02-09 | 2006-03-07 | Yanmar Co., Ltd. | Hydraulically driven working machine |
| US7735248B2 (en) | 2005-03-14 | 2010-06-15 | Yanmar Co., Ltd. | Piping struture of front work machine |
-
1989
- 1989-09-13 JP JP1235794A patent/JP2966442B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7008169B1 (en) * | 1999-02-09 | 2006-03-07 | Yanmar Co., Ltd. | Hydraulically driven working machine |
| JP2001302246A (en) * | 2000-04-24 | 2001-10-31 | Murata Mfg Co Ltd | Method of producing ceramic, and ceramic |
| US7735248B2 (en) | 2005-03-14 | 2010-06-15 | Yanmar Co., Ltd. | Piping struture of front work machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2966442B2 (en) | 1999-10-25 |
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