JPH04240115A - Production of oxide superconducting bulk material - Google Patents
Production of oxide superconducting bulk materialInfo
- Publication number
- JPH04240115A JPH04240115A JP3007034A JP703491A JPH04240115A JP H04240115 A JPH04240115 A JP H04240115A JP 3007034 A JP3007034 A JP 3007034A JP 703491 A JP703491 A JP 703491A JP H04240115 A JPH04240115 A JP H04240115A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- phase
- oxide
- current density
- basno3
- 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.)
- Withdrawn
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000013590 bulk material Substances 0.000 title abstract description 8
- 239000000843 powder Substances 0.000 claims abstract description 31
- 239000000463 material Substances 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 16
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 claims description 12
- 239000011812 mixed powder Substances 0.000 claims description 7
- 229910002113 barium titanate Inorganic materials 0.000 claims description 2
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 238000002844 melting Methods 0.000 abstract description 14
- 230000008018 melting Effects 0.000 abstract description 14
- 229910002929 BaSnO3 Inorganic materials 0.000 abstract description 6
- 230000004907 flux Effects 0.000 abstract description 6
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 abstract description 4
- 238000000465 moulding Methods 0.000 abstract description 3
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 abstract description 3
- 238000010791 quenching Methods 0.000 abstract description 3
- 230000000171 quenching effect Effects 0.000 abstract description 2
- 229910003098 YBa2Cu3O7−x Inorganic materials 0.000 abstract 1
- 239000004020 conductor Substances 0.000 abstract 1
- 238000000227 grinding Methods 0.000 abstract 1
- 229910052727 yttrium Inorganic materials 0.000 abstract 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 abstract 1
- 239000012071 phase Substances 0.000 description 45
- 238000010438 heat treatment Methods 0.000 description 15
- 239000013078 crystal Substances 0.000 description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 238000001816 cooling Methods 0.000 description 7
- 239000010419 fine particle Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 238000010583 slow cooling Methods 0.000 description 5
- 239000002887 superconductor Substances 0.000 description 5
- 239000010949 copper Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910021523 barium zirconate Inorganic materials 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 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
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】この発明は高い臨界電流密度およ
び磁場特性を有するＹ−Ｂａ−Ｃｕ−Ｏ系酸化物超電導
バルク材の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for producing a Y--Ba--Cu--O based oxide superconducting bulk material having high critical current density and magnetic field characteristics.
【０００２】酸化物超電導体は種々の形態のバルクに成
形され、超電導ベアリング、超電導磁石、磁気遮蔽など
に用いられる。[0002] Oxide superconductors are formed into various bulk shapes and used in superconducting bearings, superconducting magnets, magnetic shields, and the like.
【０００３】0003
【従来の技術】超電導の応用にとって、臨界温度が高い
というのは大きな利点となる。特に、液体窒素温度を超
えるＹＢａＣｕＯやＢｉ系、Ｔｌ系酸化物超電導体の発
見は、冷却コストの低下およびヘリウムと比べて資源的
に豊富な窒素の利用ができるなどの点で超電導の利用分
野を大きく拡大する可能性を与えている。BACKGROUND OF THE INVENTION A high critical temperature is a great advantage for superconducting applications. In particular, the discovery of YBaCuO, Bi-based, and Tl-based oxide superconductors that exceed liquid nitrogen temperatures has opened up new fields of application for superconductors in terms of lower cooling costs and the ability to utilize nitrogen, which is more abundant as a resource than helium. It offers great potential for expansion.
【０００４】しかし、超電導の応用にとっては、臨界温
度よりはむしろ使用温度における臨界電流の大きさが重
要となる。液体窒素での応用を目指すためには、この温
度での臨界電流密度の改善が必須となる。臨界電流密度
は材料固有の特性ではなく、材料の組織を変えることに
よって向上させることが可能となる。たとえば、溶融法
によって結晶配向させることで、超電導電流の妨げとな
る欠陥を除去でき、焼結法などで作製した材料に比べて
高い臨界電流密度が達成される。溶融法として、ＱＭＧ
法（新日鐵），ＭＰＭＧ法（ＩＳＴＥＣ）あるいはＭＴ
Ｇ法（ＡＴ＆Ｔ）などがある。ＱＭＧ法は、溶融−急冷
、部分溶融−徐冷工程からなっている。ＭＰＭＧ法は、
溶融−急冷−粉砕−成型、部分溶融−徐冷工程からなっ
ている。また、ＭＴＧ法は成型−溶融−徐冷工程からな
っている。However, for superconducting applications, the magnitude of the critical current at the operating temperature is more important than the critical temperature. In order to aim for application in liquid nitrogen, it is essential to improve the critical current density at this temperature. The critical current density is not an inherent property of the material, but can be improved by changing the structure of the material. For example, crystal orientation using a melting method can remove defects that impede superconducting current, and achieve a higher critical current density than materials produced using sintering methods or the like. As a melting method, QMG
Law (Nippon Steel), MPMG Law (ISTEC) or MT
There are methods such as G method (AT&T). The QMG method consists of melting-quenching and partial melting-slow cooling steps. The MPMG method is
It consists of melting-quenching-pulverization-molding and partial melting-slow cooling steps. Moreover, the MTG method consists of a molding-melting-slow cooling process.
【０００５】しかし、臨界電流密度そのものは実用レベ
ルよりもまだ低い（Ｔ＝７７Ｋ，Ｈｅ＝数Ｔで１０４
Ａ／ｃｍ２ 程度まで特性の向上が必要である）。これ
は、高い臨界電流密度を得るためには超電導電流の妨げ
となる欠陥の除去だけではなく、磁束の運動を抑えるピ
ン止め点の導入が必要であるためである。単に溶融法で
作製した場合、このようなピン止めを自然に導入される
点欠陥や転位などに頼らざるを得ないため高い臨界電流
密度が得られない。この磁束の運動を抑えるために、Ｙ
−Ｂａ−Ｃｕ−Ｏ系では非超電導相であるＹ２ ＢａＣ
ｕＯ５ 相（２１１相）を超電導相であるＹＢａ２ Ｃ
ｕ３ Ｏ７−ｘ 相（１２３相）内に微細に分散させる
ようにしている。However, the critical current density itself is still lower than the practical level (T=77K, He=104
It is necessary to improve the characteristics to about A/cm2). This is because in order to obtain a high critical current density, it is necessary not only to remove defects that impede superconducting current, but also to introduce pinning points that suppress the movement of magnetic flux. When fabricated simply by a melting method, a high critical current density cannot be obtained because such pinning must rely on naturally introduced point defects or dislocations. In order to suppress the movement of this magnetic flux, Y
-Y2 BaC which is a non-superconducting phase in the Ba-Cu-O system
uO5 phase (211 phase) is superconducting phase YBa2C
It is made to be finely dispersed within the u3O7-x phase (123 phase).
【０００６】[0006]
【発明が解決しようとする課題】前記ＱＭＧ法およびＭ
ＴＧ法では、出発原料としてＹＢａ２ Ｃｕ３ Ｏ７−
ｘ 粉を使用し溶融を行う。溶融されるとイットリュー
ム酸化物が溶融したＢａＣｕ中に生成する。このイット
リューム酸化物が粗大化するとともに、凝集する。Ｙ２
ＢａＣｕＯ５ 相はこの酸化物を核として生成するた
めに粗大な、あるいは凝集したイットリューム酸化物か
らＹ２ ＢａＣｕＯ５ 相およびその他の相の微細粒子
をＹＢａ２ Ｃｕ３ Ｏ７−ｘ相中に均一に分散するこ
とが困難である。また、ＭＰＭＧ法（ＩＳＴＥＣ）およ
びＭＴＧ法では、部分溶融処理条件が高温長時間になる
ために常電導相が粗大化したものと考えられる。この結
果、Ｙ２ ＢａＣｕＯ５ 相およびその他の相の微細粒
子による磁束のピン止め効果が十分でなく、またＹＢａ
２ Ｃｕ３ Ｏ７−ｘ 相に割れが発生し、高磁場にお
いて液体窒素温度で実用に耐える臨界電流密度が得られ
ないという問題があった。[Problem to be solved by the invention] The QMG method and M
In the TG method, YBa2 Cu3 O7- is used as a starting material.
x Perform melting using powder. Upon melting, yttrium oxide forms in the molten BaCu. This yttrium oxide becomes coarse and aggregates. Y2
Since the BaCuO5 phase is generated using this oxide as a nucleus, it is difficult to uniformly disperse fine particles of the Y2 BaCuO5 phase and other phases from coarse or aggregated yttrium oxide into the YBa2 Cu3 O7-x phase. It is. Further, in the MPMG method (ISTEC) and the MTG method, it is thought that the normal conductive phase becomes coarse because the partial melting treatment conditions are high temperature and long time. As a result, the magnetic flux pinning effect by the fine particles of the Y2 BaCuO5 phase and other phases is not sufficient, and the
There was a problem in that cracks occurred in the 2Cu3O7-x phase, and a critical current density that could withstand practical use at liquid nitrogen temperatures in a high magnetic field could not be obtained.
【０００７】そこで、この発明はＹＢａ２ Ｃｕ３ Ｏ
７−ｘ 相中にＹ２ ＢａＣｕＯ５ 相およびその他の
相の粒子を微細かつ均一に分散し、高い臨界電流密度を
得ることができる酸化物超電導バルク材の製造方法を提
供しようとするものである。[0007] Therefore, the present invention is based on YBa2 Cu3 O
The object of the present invention is to provide a method for producing an oxide superconducting bulk material in which particles of the Y2 BaCuO5 phase and other phases are finely and uniformly dispersed in the 7-x phase and a high critical current density can be obtained.
【０００８】[0008]
【課題を解決するための手段】この発明の酸化物超電導
バルク材の製造方法は、ＢａＣＯ３ 粉末とＣｕＯ粉末
との混合粉末を溶融し、急冷し、粉砕してＢａ２ Ｃｕ
３ Ｏｘ 粉末を作製する。ついで、上記Ｂａ２ Ｃｕ
３ Ｏｘ 粉末にＹ２ Ｏ３ とモル比で５％から２０
％までのＡｇ，Ｂａｘ Ｐｔｙ Ｏｚ ，ＳｉＢａＯ３
，ＧｅＢａＯ３ ，ＳｎＢａＯ３ ，ＰｂＢａＯ３
，ＢａＴｉＯ３ およびＢａＺｒＯ３ のうちの少くと
も一つとからなる混合粉末を添加して混練し、成型する
。そして、上記成型体を部分溶融熱処理し、引き続き結
晶成長熱処理し、酸素量調整熱処理する。[Means for Solving the Problems] The method for producing an oxide superconducting bulk material of the present invention involves melting a mixed powder of BaCO3 powder and CuO powder, rapidly cooling it, and pulverizing it to form Ba2 Cu powder.
3 Ox powder is prepared. Then, the above Ba2Cu
3 Ox powder and Y2 O3 in molar ratio from 5% to 20
up to % Ag, Bax Pty Oz, SiBaO3
, GeBaO3 , SnBaO3 , PbBaO3
, BaTiO3, and BaZrO3 are added, kneaded, and molded. Then, the molded body is subjected to partial melting heat treatment, followed by crystal growth heat treatment, and oxygen content adjustment heat treatment.
【０００９】図１および図２に従って、この発明を詳細
に説明する。ＢａＣＯ３ 粉末およびＣｕＯ粉末の混合
比は、Ｂａ：Ｃｕ＝（１．５〜２．５）：（２．５〜３
．５）程度が好ましい。混合粉末の溶融加熱温度は１１
００℃以上であり、加熱保持時間は３〜３０ｍｉｎ 程
度である。ＢａＣＯ３ 粉末とＣｕＯ粉末との混合粉末
を溶融、急冷することによって、凝固した塊状のＢａ２
Ｃｕ３ Ｏｘ が得られる。なお、混合粉末の溶融に
より、ＢａＣＯ３ 中のＣＯ３ は消失する。ＢａとＣ
ｕとの分離を避けるために、急冷速度は１０℃／ｓｅｃ
以上であることが望ましい。また、Ｂａ２ Ｃｕ３
Ｏｘ を粉砕して得た粉末の粒径は２００μｍ以下であ
ることが好ましい。上記Ｂａ２ Ｃｕ３ Ｏｘ 粉末に
Ｙ２ Ｏ３ とＡｇ，ＳｎＢａＯ３ ，ＳｉＢａＯ３
その他とからなる混合粉末を添加する量は、作製された
超電導バルク材がＹＢａ２ Ｃｕ３ Ｏ７−ｘ 組成ま
たはこの組成にＹＢａ２ Ｃｕ３ Ｏ７−ｘ を５０
ｍｏｌ％まで含む組成となる量である。The present invention will be explained in detail with reference to FIGS. 1 and 2. The mixing ratio of BaCO3 powder and CuO powder is Ba:Cu=(1.5-2.5):(2.5-3
．． 5) is preferable. The melting and heating temperature of the mixed powder is 11
The temperature is 00°C or higher, and the heating holding time is about 3 to 30 minutes. By melting and rapidly cooling a mixed powder of BaCO3 powder and CuO powder, solidified lumps of Ba2
Cu3Ox is obtained. Note that CO3 in BaCO3 disappears by melting the mixed powder. Ba and C
The quenching rate was 10°C/sec to avoid separation from u.
The above is desirable. Also, Ba2 Cu3
The particle size of the powder obtained by pulverizing Ox is preferably 200 μm or less. Y2 O3 and Ag, SnBaO3, SiBaO3 are added to the above Ba2 Cu3 Ox powder.
The amount of the mixed powder to be added is such that the produced superconducting bulk material has a composition of YBa2 Cu3 O7-x or 50% of YBa2 Cu3 O7-x is added to this composition.
This is the amount that results in a composition containing up to mol%.
【００１０】成型体の部分溶融熱処理では、成型体を１
０００〜１３５０℃に加熱し、０．１〜２ｈｒ程度保持
する。成型体の加熱温度が１０００℃未満では、部分溶
融はするが量的に少なく臨界電流密は向上しない。逆に
、成型体の加熱温度が１３５０℃を超えると、微細なＹ
２ ＢａＣｕＯ５ 相が得られない。また、成型体が完
全に溶融して原型をとどめない状態となり、所要の形状
のバルク材が得られない。ついで、１０５０〜１０００
℃まで比較的高い冷却速度（たとえば、５０〜１℃／ｈ
ｒ）で冷却する。結晶成長熱処理は、成型体を上記温度
１０５０〜１０００℃から９６０〜９４０℃に至るまで
徐冷する。冷却速度は２００℃／ｈｒ以下である。徐冷
速度が、２００℃／ｈｒを超えると、ＹＢａ２ Ｃｕ３
Ｏ７−ｘ 相の結晶粒が充分成長しないため、粒界が
多くなり臨界電流密度が低下する。このような熱処理に
よって、超電導相の中には細かなＹ２ ＢａＣｕＯ５
相が含まれているため組織が細かく機械的強度も改善さ
れる。酸素量調整熱処理は、成型体を酸素雰囲気中また
は空気中で冷却する。冷却速度は１０〜１℃／ｈｒ程度
である。酸素量調整熱処理では、ＹＢａ２ Ｃｕ３ Ｏ
７−ｘ 中の酸素量Ｏ７−ｘ を調整する。In the partial melting heat treatment of the molded body, the molded body is
Heat to 000 to 1350°C and hold for about 0.1 to 2 hours. If the heating temperature of the molded body is less than 1000°C, partial melting will occur, but the amount will be small and the critical current density will not improve. On the other hand, if the heating temperature of the molded body exceeds 1350°C, fine Y
2 BaCuO5 phase is not obtained. In addition, the molded body is completely melted and does not retain its original shape, making it impossible to obtain a bulk material in the desired shape. Then 1050-1000
℃ relatively high cooling rate (e.g. 50-1℃/h
Cool at r). In the crystal growth heat treatment, the molded body is slowly cooled from the above temperature of 1050 to 1000°C to 960 to 940°C. The cooling rate is 200° C./hr or less. When the slow cooling rate exceeds 200°C/hr, YBa2 Cu3
Since the crystal grains of the O7-x phase do not grow sufficiently, the number of grain boundaries increases and the critical current density decreases. Through such heat treatment, fine Y2 BaCuO5 is present in the superconducting phase.
Because it contains a phase, it has a fine structure and improves mechanical strength. In the oxygen amount adjustment heat treatment, the molded body is cooled in an oxygen atmosphere or in air. The cooling rate is about 10 to 1°C/hr. In the oxygen content adjustment heat treatment, YBa2 Cu3 O
Adjust the oxygen amount O7-x in 7-x.
【００１１】[0011]
【作用】成型体は１０００℃〜１３５０℃に加熱すると
半溶融状態となり、Ｙ２ Ｏ３ と液相（ＢａＣｕ酸化
物） が反応し、Ｙ２Ｏ３ を核として針状の細かいＹ
２ ＢａＣｕＯ５ 相が成長する。このＹ２ ＢａＣｕ
Ｏ５ 相は分断されて微細な相となる。また、Ａｇ，Ｓ
ｎＢａＯ５ ，ＳｉＢａＯ３ その他の相は部分溶融状
態を経ても反応することもなく、添加時の粒径を維持し
微粒子が分散する。半溶融状態では、繊維状Ｙ２ Ｂａ
ＣｕＯ５相が液相を吸収するため、成型体の形はほぼ維
持される。半溶融状態の成型体を徐冷すると、Ｙ２ Ｂ
ａＣｕＯ５ 相と液相との包晶反応によりＹＢａ２ Ｃ
ｕ３ Ｏ７−ｘ 相が析出する。この状態から、さらに
徐冷をすることによって核生成を抑制し、結晶の成長を
律速することによって粒界の少ない、すなわち大きな結
晶粒が得られる。このときできる組織はＹＢａ２ Ｃｕ
３ Ｏ７−ｘ 相中に細かいＹ２ ＢａＣｕＯ５ 相お
よびＡｇ，Ｂａｘ Ｐｔｙ Ｏｚ ，ＳｉＢａＯ３ あ
るいはその他の相の微粒子を含んでおり、この微細分散
物の存在により、結晶成長を含む熱処理中に生ずる応力
を分散させることによって粒界および割れが少なく、方
位のそろった数ミリ以上の結晶の集合体となる。１３５
０℃を超える高温でＹを含むＢａＣｕ組成のものを溶融
処理をすることがないので、Ｙ２ Ｏ３ の凝集や、粗
大化がないためにＹ２ ＢａＣｕＯ５ 相は微細となる
。また、ＹＢａ２ Ｃｕ３ Ｏ７−ｘ 相中のＹ２ Ｂ
ａＣｕＯ５ 相およびＡｇ，Ｂａｘ Ｐｔｙ Ｏｚ ，
ＳｉＢａＯ３ その他の相の量の調整は、主に初期の添
加量で調整する。[Operation] When the molded body is heated to 1000°C to 1350°C, it becomes a semi-molten state, and Y2O3 and the liquid phase (BaCu oxide) react, forming needle-like fine Y2O3 cores.
2 BaCuO5 phase grows. This Y2 BaCu
The O5 phase is divided into fine phases. Also, Ag,S
The nBaO5, SiBaO3, and other phases do not react even after passing through a partially melted state, and maintain the particle size at the time of addition, and the fine particles are dispersed. In the semi-molten state, fibrous Y2Ba
Since the CuO5 phase absorbs the liquid phase, the shape of the molded product is almost maintained. When the semi-molten molded body is slowly cooled, Y2 B
Due to the peritectic reaction between the aCuO5 phase and the liquid phase, YBa2C
A u3 O7-x phase precipitates. From this state, slow cooling is further performed to suppress nucleation and to control the rate of crystal growth, thereby obtaining large crystal grains with few grain boundaries. The structure formed at this time is YBa2Cu
The 3 O7-x phase contains fine Y2 BaCuO5 phase and fine particles of Ag, Bax Pty Oz, SiBaO3, or other phases, and the presence of this fine dispersion disperses stress generated during heat treatment including crystal growth. This results in an aggregate of crystals several millimeters or more in size with fewer grain boundaries and cracks and with uniform orientation. 135
Since the BaCu composition containing Y is not melted at a high temperature exceeding 0° C., the Y2 BaCuO5 phase becomes fine because there is no aggregation or coarsening of Y2 O3. In addition, Y2 B in the YBa2 Cu3 O7-x phase
aCuO5 phase and Ag, Bax Pty Oz,
The amount of SiBaO3 and other phases is adjusted mainly by the initial amount added.
【００１２】Ｙ２ ＢａＣｕＯ５ 相およびＡｇ，Ｂａ
ｘＰｔｙ Ｏｚ ，ＳｉＢａＯ３ あるいはその他の相
が微細であると、超電導体を貫通する磁束がＹ２ Ｂａ
ＣｕＯ５ 相およびその他の相と鎖交する点が増し、ピ
ン止め効果は高くなる。また、割れも少なくなる。この
結果、臨界電流密度は向上する。[0012] Y2 BaCuO5 phase and Ag, Ba
When xPtyOz, SiBaO3, or other phases are fine, the magnetic flux penetrating the superconductor becomes
The number of points interlinked with the CuO5 phase and other phases increases, and the pinning effect becomes higher. Moreover, cracks are also reduced. As a result, the critical current density is improved.
【００１３】[0013]
【実施例】ＢａＣｏ３ 粉末、およびＣｕＯ粉末をモル
比で１：１．５になるように混合した粉末を１４００℃
で溶融し、銅ハース上で急冷した。得られたＢａＣｕ酸
化物成型体を粉砕して１００メッシュ以下の粉末を製造
した。これとは別にＢａＣＯ３ 粉末とＳｎＯ２ 粉末
をモル比で１：１になるようにした混合粉を大気中で１
１００℃、５時間の熱処理を加えてＢａＳｎＯ３ を得
る。これを充分に粉砕をして１０μｍ以下の粉末にする
。先のＢａＣｕ酸化物にＹ２ Ｏ３ 粉末を加え、Ｙ：
Ｂａ：Ｃｕの比（モル比）１．２：２：３に成るように
し、さらに上記のＢａＳｎＯ３ 粉末を５％（モル％）
添加した。添加後、充分に混練した後に金型に充填、プ
レス、ＣＩＰして直径３ｃｍ、厚さ１．５ｃｍのペレッ
トに成型した。[Example] A powder prepared by mixing BaCo3 powder and CuO powder at a molar ratio of 1:1.5 was heated to 1400°C.
and quenched on a copper hearth. The obtained BaCu oxide molded body was pulverized to produce a powder of 100 mesh or less. Separately, a mixed powder of BaCO3 powder and SnO2 powder at a molar ratio of 1:1 was prepared in the atmosphere.
BaSnO3 is obtained by heat treatment at 100°C for 5 hours. This is thoroughly ground to a powder of 10 μm or less. Add Y2 O3 powder to the previous BaCu oxide, Y:
The Ba:Cu ratio (mole ratio) was adjusted to 1.2:2:3, and the above BaSnO3 powder was added at 5% (mol%).
Added. After addition, the mixture was sufficiently kneaded, filled into a mold, pressed, and CIPed to form pellets with a diameter of 3 cm and a thickness of 1.5 cm.
【００１４】上記ペレットを１２００℃、１時間の加熱
保持して成型体を部分溶融させる。この状態から１００
０℃まで２００℃／ｈｒで冷却した。１０００℃近傍か
らは超電導体ＹＢａ２ ＣＵ３ Ｏ７−ｘ 結晶が成長
をはじめ９６０〜９４０℃程度で停止する。この温度域
を１℃／ｈｒで徐冷してＹＢａ２ Ｃｕ３ Ｏ７−ｘ
結晶の核生成を抑制し、結晶成長律速にして大きな結晶
を得た。９４０℃以降は常温まで１００℃／ｈｒの速度
で冷却し、この後に酸素量調整のため酸素気流中で６０
０℃まで再加熱を行い、６００℃８時間保持後２００℃
まで１０℃／ｈｒの速度で冷却して酸素調整熱処理を行
った。[0014] The above pellets are heated and held at 1200°C for 1 hour to partially melt the molded body. 100 from this state
It was cooled to 0°C at a rate of 200°C/hr. The superconductor YBa2 CU3 O7-x crystal begins to grow from around 1000°C and stops at about 960 to 940°C. This temperature range was slowly cooled at 1°C/hr to produce YBa2 Cu3 O7-x.
Large crystals were obtained by suppressing crystal nucleation and controlling the crystal growth rate. After 940℃, it is cooled to room temperature at a rate of 100℃/hr, and then heated for 60 minutes in an oxygen stream to adjust the amount of oxygen.
Reheat to 0℃, hold at 600℃ for 8 hours, then heat to 200℃
Oxygen adjustment heat treatment was performed by cooling at a rate of 10° C./hr.
【００１５】この処理によって得られたミクロ組織は、
２μｍ程度のＢａＳｎＯ３ （ＥＤＸ分析による同定）
が均一に分散した良好な結晶であった。この結晶は、Ｂ
ａＳｎＯ３ が添加されても超電導状態になる臨界温度
は−９２℃を示し、添加による劣化はない（図３）。ま
た、このときの臨界電流密度を試料振動型磁力計を用い
て測定した磁気ヒステリシス曲線から換算した結果では
７７Ｋ１テスラにおける臨界電流密度は９．７×１０３
Ａ／ｃｍ２ と高い値が得られた。[0015] The microstructure obtained by this treatment is
BaSnO3 of about 2μm (identification by EDX analysis)
The crystals were uniformly dispersed and had good quality. This crystal is B
Even when aSnO3 is added, the critical temperature at which it becomes superconducting is -92°C, and there is no deterioration due to the addition (Figure 3). In addition, the critical current density at this time was converted from the magnetic hysteresis curve measured using a sample vibrating magnetometer, and the critical current density at 77K1 Tesla was 9.7 x 103
A high value of A/cm2 was obtained.
【００１６】[0016]
【発明の効果】この発明によれば、ＹＢａ２ Ｃｕ３
Ｏ７−ｘ 相中にＹ２ ＢａＣｕＯ５ 相その他の相の
微細粒子が均一に分布した超電導バルク材を得ることが
できる。また、得られたＹＢａ２ Ｃｕ３ Ｏ７−ｘ
相は、一つの粒径が数ミリと大きく、粒界および割れも
少ない。この結果、Ｙ２ ＢａＣｕＯ５ 相その他の相
の微細粒子による磁束のピン止め効果が向上し、高磁場
中でも従来法と比較して高い臨界電流密度を得ることが
できる。[Effect of the invention] According to this invention, YBa2 Cu3
A superconducting bulk material in which fine particles of the Y2 BaCuO5 phase and other phases are uniformly distributed in the O7-x phase can be obtained. In addition, the obtained YBa2 Cu3 O7-x
The phase has a large grain size of several millimeters, and there are few grain boundaries and cracks. As a result, the magnetic flux pinning effect by fine particles of the Y2 BaCuO5 phase and other phases is improved, and a higher critical current density can be obtained than in the conventional method even in a high magnetic field.
【図１】この発明の工程を示すフローチャートである。FIG. 1 is a flowchart showing the steps of the invention.
【図２】この発明の工程を示す模式図である。FIG. 2 is a schematic diagram showing the steps of the present invention.
【図３】４端子法によって測定した臨界温度測定図であ
る。FIG. 3 is a critical temperature measurement diagram measured by a four-terminal method.
Claims (1)
合粉末を溶融し、急冷し、粉砕してＢａ２ Ｃｕ３ Ｏ
ｘ 粉末を作製し、前記Ｂａ２ Ｃｕ３ Ｏｘ 粉末に
Ｙ２ Ｏ３ とモル比で５％から２０％までのＡｇ，Ｂ
ａｘ Ｐｔｙ Ｏｚ ，ＳｉＢａＯ３ ，ＧｅＢａＯ３
，ＳｎＢａＯ３ ，ＰｂＢａＯ３ ，ＢａＴｉＯ３
およびＢａＺｒＯ３ のうちの少くとも一つとからなる
混合粉末を添加して混練し、成型し、前記成型体を部分
溶融熱処理し、引き続き結晶成長熱処理し、酸素量調整
熱処理することを特徴とする酸化物超電導バルク材の製
造方法。[Claim 1] A mixed powder of BaCO3 powder and CuO powder is melted, rapidly cooled, and pulverized to form Ba2 Cu3 O.
x powder was prepared, and Y2 O3 and Ag, B in a molar ratio of 5% to 20% were added to the Ba2 Cu3 Ox powder.
ax Pty Oz, SiBaO3, GeBaO3
, SnBaO3 , PbBaO3 , BaTiO3
and BaZrO. A method for manufacturing superconducting bulk materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3007034A JPH04240115A (en) | 1991-01-24 | 1991-01-24 | Production of oxide superconducting bulk material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3007034A JPH04240115A (en) | 1991-01-24 | 1991-01-24 | Production of oxide superconducting bulk material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04240115A true JPH04240115A (en) | 1992-08-27 |
Family
ID=11654757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3007034A Withdrawn JPH04240115A (en) | 1991-01-24 | 1991-01-24 | Production of oxide superconducting bulk material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04240115A (en) |
-
1991
- 1991-01-24 JP JP3007034A patent/JPH04240115A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0440289B2 (en) | ||
| JP2839415B2 (en) | Method for producing rare earth superconducting composition | |
| US5508253A (en) | REBa2 Cu3 O7-y type oxide superconductive material having high critical current density and process for preparation thereof | |
| WO1990013517A1 (en) | Oxide superconductor and method of producing the same | |
| JPH0558626A (en) | Oxide superconductor and its production | |
| US5395820A (en) | Oxide superconductor and process for producing the same | |
| JPH04224111A (en) | Rare earth type oxide superconductor and its production | |
| US5430010A (en) | Process for preparing oxide superconductor | |
| JPH04240115A (en) | Production of oxide superconducting bulk material | |
| JP2914799B2 (en) | Manufacturing method of oxide superconducting bulk material | |
| JPH07115924B2 (en) | Method for manufacturing oxide superconductor | |
| JP3115696B2 (en) | Manufacturing method of oxide superconductor having large magnetic levitation force | |
| JPH05279033A (en) | Production of oxide superconductor having high critical current density | |
| JP3115695B2 (en) | Manufacturing method of oxide superconductor having large magnetic levitation force | |
| JPH04119968A (en) | Production of oxide superconductor | |
| JPH10245223A (en) | Oxide superconductor and its production | |
| JP3159764B2 (en) | Manufacturing method of rare earth superconductor | |
| Yanmaz et al. | Melt processing of powdered arc-cast YBa2Cu3Oy materials | |
| JP2931446B2 (en) | Method for producing rare earth oxide superconductor | |
| JPH04254466A (en) | Production of yittrium-base superconducting bulk material | |
| JP2004203727A (en) | Oxide superconductor having high critical current density | |
| JP2006036574A (en) | METHOD FOR MANUFACTURING RE-Ba-Cu-O-BASED OXIDE SUPERCONDUCTOR | |
| JPH08325013A (en) | Neodymium based oxide superconducting formed body and its manufacture | |
| JPH04243917A (en) | Preparation of oxide superconducting sintered compact | |
| JPH0421505A (en) | Ceramic superconductor and production thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19980514 |