JP2803819B2 - Manufacturing method of oxide superconductor - Google Patents
Manufacturing method of oxide superconductorInfo
- Publication number
- JP2803819B2 JP2803819B2 JP63093560A JP9356088A JP2803819B2 JP 2803819 B2 JP2803819 B2 JP 2803819B2 JP 63093560 A JP63093560 A JP 63093560A JP 9356088 A JP9356088 A JP 9356088A JP 2803819 B2 JP2803819 B2 JP 2803819B2
- Authority
- JP
- Japan
- Prior art keywords
- composition
- bisrcacuo
- based oxide
- heat treatment
- oxide 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.)
- Expired - Lifetime
Links
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
- Inorganic Compounds Of Heavy Metals (AREA)
- Compositions Of Oxide Ceramics (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］ この発明は酸化物超電導体、特にBiSrCaCuO系超電導
体の製造方法に関する。酸化物超電導体は線状あるいは
膜状に成形され、電気機器や電子デバイスなどに用いら
れる。The present invention relates to a method for producing an oxide superconductor, particularly a BiSrCaCuO-based superconductor. The oxide superconductor is formed into a linear shape or a film shape, and is used for electric equipment and electronic devices.
［従来の技術］ 臨界温度が90Kを越えるYBaCuO系酸化物超電導体の発
見以来、世界的な研究が展開され、臨界温度が100Kを越
えるBiSrCaCuO系酸化物超電導体の発見（前田弘ら、App
lied Physics Letters,vol.28,1988）に至っている。[Prior art] Since the discovery of YBaCuO-based oxide superconductors with a critical temperature exceeding 90K, worldwide research has been conducted, and the discovery of BiSrCaCuO-based oxide superconductors with a critical temperature exceeding 100K (Hiroshi Maeda et al., App.
lied Physics Letters, vol. 28, 1988).
このBiSrCaCuO系酸化物超電導体の組成はBiSrCaCu2Ox
であるといわれているが、このBi系の酸化物は単相が得
にくく、臨界温度は高いが臨界電流密度は低いという欠
点を有している。The composition of this BiSrCaCuO-based oxide superconductor is BiSrCaCu 2 O x
However, this Bi-based oxide has a drawback that it is difficult to obtain a single phase and the critical temperature is high but the critical current density is low.
BiSrCaCu2Ox超電導体の製造は上記文献によれば、Bi2
O3,SrCO3,CaCO3およびCuO粉を上記組成比となるように
混合し、800℃〜870℃で５時間仮焼し、粉砕後成形した
のち、870℃で９時間空気または酸素雰囲気中に焼結し
て製造される。The production of BiSrCaCu 2 O x superconductor is based on Bi 2
O 3 , SrCO 3 , CaCO 3 and CuO powder are mixed so as to have the above composition ratio, calcined at 800 to 870 ° C. for 5 hours, pulverized and molded, and then at 870 ° C. for 9 hours in an air or oxygen atmosphere. It is manufactured by sintering.
［発明が解決しようとする課題］ しかし、上記方法でBiSrCaCuO系酸化物超電導体を製
造する超電導相の割合が低く、77Kにおいてさえも臨界
電流密度はかなり低くなってしまう。これは、通常の焼
結方法でこの酸化物超電導体を製造すると、超電導相が
殆ど生成しないためである。[Problems to be Solved by the Invention] However, the proportion of the superconducting phase for producing the BiSrCaCuO-based oxide superconductor by the above method is low, and even at 77K, the critical current density is considerably reduced. This is because, when this oxide superconductor is manufactured by a usual sintering method, a superconducting phase is hardly generated.
そこで、この発明はBi系酸化物超電導体において、超
電導相の割合を高くして、臨界電流密度の高い酸化物超
電導体の製造方法を提供しようとするものである。Accordingly, an object of the present invention is to provide a method of manufacturing an oxide superconductor having a high critical current density by increasing the ratio of a superconducting phase in a Bi-based oxide superconductor.
［課題を解決するための手段］ 第１の発明は、酸化物超電導体を製造する方法におい
て、熱処理温度850〜920℃より低い融点を有する組成の
BiSrCaCuO系酸化物の粉粒と前記熱処理温度より高い融
点を有する組成のBiSrCaCuO系酸化物の粉粒とをそれぞ
れを作製し、BiO1.5、（SrCaO）、CuOの擬３元系状態図
での組成が金属元素割合（BiO1.5、（SrCa）Ｏ、CuO）
で（50、30、20）、（40、20、40）、（20、30、50）、
（20、50、30）（24、52、24）、（30、50、20）の６点
を結ぶ線で囲まれた領域の組成になる割合で前記粉粒を
組み合わせ、前記熱処理温度で部分溶融熱処理すること
を特徴としている。[Means for Solving the Problems] A first invention is a method for producing an oxide superconductor, which comprises a composition having a melting point lower than a heat treatment temperature of 850 to 920 ° C.
Powder particles of BiSrCaCuO-based oxide and powder particles of BiSrCaCuO-based oxide having a melting point higher than the heat treatment temperature were prepared, respectively, and the compositions of BiO 1.5 , (SrCaO), and CuO in a pseudo-ternary phase diagram Is the metal element ratio (BiO 1.5 , (SrCa) O, CuO)
(50, 30, 20), (40, 20, 40), (20, 30, 50),
(20, 50, 30) Combine the powder and granules at a ratio that results in the composition of the region surrounded by the line connecting the six points of (24, 52, 24) and (30, 50, 20), It is characterized by a fusion heat treatment.
また、第２の発明は、BiSrCaCuO系酸化物超電導体を
製造する方法において、熱処理温度850〜920℃より低い
融点を有する組成のBiSrCaCuO系酸化物の成形体と前記
熱処理温度より高い融点を有する組成のBiSrCaCuO系酸
化物の成形体とをそれぞれ作製し、BiO1.5、（SrCa
O）、CuOの擬３元系状態図での組成が金属元素割合（Bi
O1.5、（SrCa）Ｏ、CuO）で（50、30、20）、（40、2
0、40）、（20、30、50）、（20、50、30）、（24、5
2、24）、（30、50、20）の６点を結ぶ線で囲まれた領
域の組成になる割合で前記成形体を組み合わせ、前記熱
処理温度で部分溶融熱処理することを特徴としている。Further, a second invention provides a method for producing a BiSrCaCuO-based oxide superconductor, comprising: a molded body of a BiSrCaCuO-based oxide having a melting point lower than 850 to 920 ° C .; and a composition having a melting point higher than the heat treatment temperature. BiSrCaCuO-based oxide compacts were prepared respectively, and BiO 1.5 , (SrCa
O), the composition of CuO in the quasi-ternary phase diagram is the ratio of metal elements (Bi
O 1.5 , (SrCa) O, CuO) (50, 30, 20), (40, 2
0, 40), (20, 30, 50), (20, 50, 30), (24, 5)
The method is characterized in that the molded bodies are combined in a ratio that results in a composition of a region surrounded by a line connecting the six points of (2, 24) and (30, 50, 20), and a partial melting heat treatment is performed at the heat treatment temperature.
［作用］ 以下図面を用いて本発明を説明する。第１図はBiO1.5
−（Sr,Ca）Ｏ−CuOを頂点とする擬三元系状態図であ
る。図中に斜線で示した範囲の組成でTcの高い超電導特
性が得られる。SrとCaの組成はSrは25％から75％の範囲
でなければならない。この斜線部の組成で焼結を行い酸
化物超電導体を生成させると、単一相はなかなか得られ
ず、混相状態となる。しかも超電導相もTcが110Kと80K
の相に別れてしまい、しかも110Kの相はわずかしか生成
しないため、臨界電流密度は非常に低くなる。110Kの相
は融点の近くで長時間、熱処理することによってある程
度成長させることは可能であるが、相間の結合は悪く臨
界電流密度は高くならない。[Operation] The present invention will be described below with reference to the drawings. Fig. 1 shows BiO 1.5
FIG. 4 is a pseudo-ternary phase diagram having-(Sr, Ca) O-CuO as a vertex. A superconducting characteristic with a high Tc can be obtained with the composition in the range shown by hatching in the figure. The composition of Sr and Ca should be in the range of 25% to 75% Sr. When an oxide superconductor is produced by sintering with the composition of the hatched portion, a single phase is hardly obtained and a mixed phase is formed. Moreover, the superconducting phase also has Tc of 110K and 80K
The critical current density is very low because the phase of 110K is generated only slightly. The 110K phase can be grown to some extent by heat treatment near the melting point for a long time, but the coupling between the phases is poor and the critical current density does not increase.
そこで例えば第１図に○と×で示した組成のBiSrCaCu
O系の化合物を予め作製しておき、これらの組み合わせ
で斜線部の組成の化合物が生成するようにする。この
時、850〜920℃で反応させると○で示した組成の化合物
は溶けないが、×で示した組成の化合物は溶融する。そ
の結果、ちょうど×の組成の化合物の溶融した状態の中
で○の組成の化合物との反応が起こる。このようにして
作製された超電導相は臨界温度が高く、また斜線部の組
成のものを単に焼結した場合よりも超電導相の割合も高
くなるため臨界電流密度が改善される。また本発明の方
法によれば、上記反応により製造するので、原料の粒径
が1mmを超しても従来のYBaCuO系を代表する酸化物超電
導体のように臨界電流密度の高い材料が得られという効
果がある。また、反応させる方法も粉同士をつめてもよ
いし、別々の焼結体を作製してから重ね合わせてもよ
い。Therefore, for example, BiSrCaCu having the composition indicated by ○ and × in FIG.
O-based compounds are prepared in advance, and a compound having a composition indicated by oblique lines is formed by combining these compounds. At this time, when the reaction is carried out at 850 to 920 ° C., the compound having the composition indicated by ○ does not melt, but the compound having the composition indicated by X melts. As a result, a reaction with the compound having the composition of O occurs in the molten state of the compound having the composition of X. The superconducting phase thus produced has a high critical temperature, and the ratio of the superconducting phase is higher than that obtained by simply sintering the composition having the shaded portion, so that the critical current density is improved. Further, according to the method of the present invention, since the material is produced by the above reaction, a material having a high critical current density can be obtained as in the case of a conventional YBaCuO-based oxide superconductor even if the particle size of the raw material exceeds 1 mm. This has the effect. The method of reacting may be such that the powders are packed together, or separate sintered bodies are produced and then superposed.
［実施例］ （実施例１） Bi2O3,SrCO3,CaCO3,CuOを原料として第２図の三元系
状態図に○および×で示したBiSr4Ca4Cu5Ox（1445）お
よびBi6Sr3Ca3CuOx（6331）の組成となるように混合し
た。前者が高融点、後者が低融点の酸化物であり、熱処
理温度（880℃）において前者は固体であり、後者は液
体となる組成物である。これら原料粉を825℃で仮焼
し、これらふたつの材料が重なるようにしておき、880
℃にて4h熱処理後700℃まで100℃/hで徐冷して空冷し
た。できた試料は完全に融合しており、Tcoffsetで93K
を示し、磁化率から見積ったJcは77Kで104A/cm2であっ
た。[Examples] (Example 1) BiSr 4 Ca 4 Cu 5 O x (1445) indicated by ○ and × in the ternary phase diagram of FIG. 2 using Bi 2 O 3 , SrCO 3 , CaCO 3 , and CuO as raw materials ) And Bi 6 Sr 3 Ca 3 CuO x (6331). The former is an oxide having a high melting point and the latter is an oxide having a low melting point. At a heat treatment temperature (880 ° C.), the former is a solid and the latter is a liquid. The raw material powder is calcined at 825 ° C so that these two materials overlap, and 880
After heat treatment at ℃ for 4 h, the mixture was gradually cooled to 700 ℃ at 100 ℃ / h and air-cooled. The resulting sample is completely fused and has a Tc offset of 93K
The Jc estimated from the magnetic susceptibility was 10 4 A / cm 2 at 77K.
なおこれら原料を合わせて混練し、仮焼、焼結したも
のではTcoffsetが82Kで77KでのJcは100A/cm2以下であっ
た。In addition, these materials were kneaded together, calcined, and sintered, and had a Tc offset of 82 K and a Jc at 77 K of 100 A / cm 2 or less.
（実施例２） 実施例１と同様にして融点の高いBiSrCa2Cu3Ox（112
3）と融点の低いBi3Sr2CaCuOx（3211）の組成の成形体
を作製し、同様の処理を施した。得られた試料は完全に
融合しており、Tcoffsetで91Kを示し、磁化率から見積
ったJcは77Kで103A/cm2を示した。(Example 2) In the same manner as in Example 1, BiSrCa 2 Cu 3 O x (112
A molded body having the composition of 3) and Bi 3 Sr 2 CaCuO x (3211) having a low melting point was prepared and subjected to the same treatment. The obtained sample was completely fused, showed 91 K in Tc offset , and Jc estimated from the magnetic susceptibility showed 10 3 A / cm 2 at 77 K.
（実施例３） 実施例１と同様にして第３図の状態図で示した融点の
高い組成（○で示してある）を融点の低い組成（×で示
してある）の組み合わせで、両者を合成するとBi4Sr3Ca
3Cu4Oxの組成となるようにして熱処理を900℃で4h酸素
中で行った。Tcおよび77KにおけるJcの結果を第１表に
示す。ほぼ同様のTcとJc（77K,200G）が得られている。
この組成で単独に焼結した場合は、Tcoffsetが80Kで77K
でのJcは10A/cm2以下である。Example 3 In the same manner as in Example 1, the composition having a high melting point (shown by ○) shown in the phase diagram of FIG. When synthesized, Bi 4 Sr 3 Ca
The heat treatment was performed at 900 ° C. for 4 hours in oxygen to obtain a composition of 3 Cu 4 O x . Table 1 shows the results of Jc at Tc and 77K. Almost the same Tc and Jc (77K, 200G) are obtained.
When sintered alone with this composition, Tc offset is 80K and 77K
Is 10 A / cm 2 or less.
［発明の効果］ 本発明によれば熱処理温度において固体である組成の
BiSrCaCuO系酸化物と液体であるBiSrCaCuO系酸化物を重
ね合わせて熱処理して超電導物質を作るので熱処理温度
において固体である物質の囲りに全体的に均質に液体が
浸透して均一な組成のBiSrCaCuO系酸化物の超電導物質
ができる。その結果臨界温度の高い超電導相の割合が増
加し、臨界電流密度の高い酸化物系超電導体が得られ
る。 [Effect of the Invention] According to the present invention, a composition which is solid at a heat treatment temperature
BiSrCaCuO-based oxide and liquid BiSrCaCuO-based oxide are superimposed and heat-treated to produce a superconducting material, so that the liquid uniformly penetrates uniformly around the solid material at the heat treatment temperature and has a uniform composition BiSrCaCuO A superconducting oxide-based material is produced. As a result, the ratio of the superconducting phase having a high critical temperature increases, and an oxide superconductor having a high critical current density can be obtained.
また上記の反応によって超電導物質が得られるので、
従来超電導体を作る上でポイントとなっていた原料の粒
度をサブミクロンまで微粉砕する必要がなく粒径が1mm
を超えても、臨界電流密度の高い酸化物系超電導体が得
られるという効果もあり、工業的にBiSrCaCuO系酸化物
を製造する見通しが得られた。Also, a superconducting substance is obtained by the above reaction,
The particle size of the raw material, which has been the point of making superconductors in the past, is 1 mm, without the need for fine grinding to the submicron size.
Even when the temperature exceeds 1, there is also an effect that an oxide-based superconductor having a high critical current density can be obtained, and the prospect of industrially producing BiSrCaCuO-based oxides has been obtained.
第１図は本発明の概念図、第２図はBiO1.5−（Ca0.5,Sr
0.5）Ｏ−CuOで頂点をとった三元系状態図で本発明の実
施例１の試料の組成を示した図、第３図は第２図と同様
の三元系状態図で実施例３の試料の組成が番号で示され
た図である。なお○が融点の高い組成、×が融点の低い
組成である。FIG. 1 is a conceptual diagram of the present invention, and FIG. 2 is BiO 1.5 − (Ca 0.5 , Sr
0.5 ) A diagram showing the composition of the sample of Example 1 of the present invention in a ternary phase diagram having a peak at O-CuO, and FIG. 3 is a ternary phase diagram similar to FIG. Is a diagram in which the composition of each sample is indicated by a number. ○ indicates a composition having a high melting point, and X indicates a composition having a low melting point.
───────────────────────────────────────────────────── 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 - 57/00 C30B 1/00 - 35/00 H01L 39/00 - 39/24 H01B 12/00──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 6 , DB name) C01G 1/00-57/00 C30B 1/00-35/00 H01L 39/00-39/24 H01B 12 / 00
Claims (2)
法において、熱処理温度850〜920℃より低い融点を有す
る組成のBiSrCaCuO系酸化物の粉粒と、前記熱処理温度
より高い融点を有する組成のBiSrCaCuO系酸化物の粉粒
とをそれぞれ作製し、BiO1.5、（SrCaO）、CuOの擬３元
系状態図での組成が金属元素割合（BiO1.5、（SrCa）
Ｏ、CuO）で（50、30、20）、（40、20、40）、（20、3
0、50）、（20、50、30）、（24、52、24）、（30、5
0、20）の６点を結ぶ線で囲まれた領域の組成になる割
合で前記粉粒を組み合わせ、前記熱処理温度で部分溶融
熱処理することを特徴とするBiSrCaCuO系酸化物超電導
体の製造方法。1. A method for producing a BiSrCaCuO-based oxide superconductor, comprising a BiSrCaCuO-based oxide powder having a melting point lower than 850-920 ° C. and a BiSrCaCuO-based composition having a melting point higher than the heat-treating temperature. And oxide particles, respectively, and the composition of BiO 1.5 , (SrCaO), and CuO in the pseudo ternary phase diagram is the ratio of metal elements (BiO 1.5 , (SrCa)
(50, 30, 20), (40, 20, 40), (20, 3)
0, 50), (20, 50, 30), (24, 52, 24), (30, 5)
0, 20). A method for producing a BiSrCaCuO-based oxide superconductor, comprising combining the above-mentioned powder particles in such a ratio as to give a composition in a region surrounded by a line connecting the six points and performing partial melting heat treatment at the heat treatment temperature.
法において、熱処理温度850〜920℃より低い融点を有す
る組成のBiSrCaCuO系酸化物の成形体と、前記熱処理温
度より高い融点を有する組成のBiSrCaCuO系酸化物の成
形体とをそれぞれ作製し、BiO1.5、（SrCaO）、CuOの擬
３元系状態図での組成が金属元素割合（BiO1.5、（SrC
a）Ｏ、CuO）で（50、30、20）、（40、20、40）、（2
0、30、50）、（20、50、30）、（24、52、24）、（3
0、50、20）の６点を結ぶ線で囲まれた領域の組成にな
る割合で前記成形体を組み合わせ、前記熱処理温度で部
分溶融熱処理することを特徴とするBiSrCaCuO系酸化物
超電導体の製造方法。2. A method for producing a BiSrCaCuO-based oxide superconductor, comprising: a molded body of a BiSrCaCuO-based oxide having a melting point lower than 850 to 920 ° C .; and a BiSrCaCuOO composition having a melting point higher than the heat-treating temperature. And a compact in the pseudo ternary phase diagram of BiO 1.5 , (SrCaO), and CuO, respectively, and the metal element ratios (BiO 1.5 , (SrCO)
a) O, CuO) (50, 30, 20), (40, 20, 40), (2
0, 30, 50), (20, 50, 30), (24, 52, 24), (3
(0, 50, 20) Production of a BiSrCaCuO-based oxide superconductor characterized in that the compacts are combined in such a ratio as to have a composition of a region surrounded by a line connecting the six points and subjected to partial melting heat treatment at the heat treatment temperature. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63093560A JP2803819B2 (en) | 1988-04-18 | 1988-04-18 | Manufacturing method of oxide superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63093560A JP2803819B2 (en) | 1988-04-18 | 1988-04-18 | Manufacturing method of oxide superconductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01270561A JPH01270561A (en) | 1989-10-27 |
| JP2803819B2 true JP2803819B2 (en) | 1998-09-24 |
Family
ID=14085633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63093560A Expired - Lifetime JP2803819B2 (en) | 1988-04-18 | 1988-04-18 | Manufacturing method of oxide superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2803819B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0687611A (en) * | 1992-09-04 | 1994-03-29 | Hitachi Ltd | Oxide superconductor and production thereof and wire rod thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01242473A (en) * | 1988-03-24 | 1989-09-27 | Showa Denko Kk | Production of joined superconducting body |
-
1988
- 1988-04-18 JP JP63093560A patent/JP2803819B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01270561A (en) | 1989-10-27 |
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