JPH02229787A - Production of oxide superconductor - Google Patents
Production of oxide superconductorInfo
- Publication number
- JPH02229787A JPH02229787A JP1006375A JP637589A JPH02229787A JP H02229787 A JPH02229787 A JP H02229787A JP 1006375 A JP1006375 A JP 1006375A JP 637589 A JP637589 A JP 637589A JP H02229787 A JPH02229787 A JP H02229787A
- Authority
- JP
- Japan
- Prior art keywords
- oxide superconductor
- single crystal
- bismuth
- oxide
- seed crystal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002887 superconductor Substances 0.000 title claims abstract description 46
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000013078 crystal Substances 0.000 claims abstract description 76
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 32
- 238000000034 method Methods 0.000 claims abstract description 14
- 239000002994 raw material Substances 0.000 claims abstract description 12
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 4
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 3
- 229910052802 copper Inorganic materials 0.000 claims abstract description 3
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 3
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 31
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 6
- 239000010949 copper Substances 0.000 claims description 5
- 239000011575 calcium Substances 0.000 claims description 4
- 239000007788 liquid Substances 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 238000009835 boiling Methods 0.000 claims 1
- 239000000843 powder Substances 0.000 description 7
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 239000005751 Copper oxide Substances 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- AXTYOFUMVKNMLR-UHFFFAOYSA-N dioxobismuth Chemical compound O=[Bi]=O AXTYOFUMVKNMLR-UHFFFAOYSA-N 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- WMWLMWRWZQELOS-UHFFFAOYSA-N bismuth(III) oxide Inorganic materials O=[Bi]O[Bi]=O WMWLMWRWZQELOS-UHFFFAOYSA-N 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000007716 flux method Methods 0.000 description 1
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-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
Landscapes
- Superconductors And Manufacturing Methods Therefor (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
ｒ産業上の利用分野』
本発明は酸化物超伝導体の作製方法に関するものである
。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing an oxide superconductor.
ｒ従来の技術』
ビスマス、ストロンチウム、カルシウム、銅、酸素から
なる酸化物超伝導体（以下ビスマス系酸化物超伝導体と
よぶ）は、高温超伝導体として知られ、Ｔｃ〜８０Ｋの
低Ｔｃ相（化学式はＢｉ．ＳｒｚｃａＣｕｚＯｓ＋ｘＳ
Ｃ軸長約３０オングストローム）と、Ｔｃ〜１１０Ｋの
高Ｔｃ相（Ｂｉ．ＳｒｚＣ ａ ｚｃ ｕｓｏ＋ｏ＋ｗ
、Ｃ軸長約３６オングストローム）があることがわかっ
ている。現在この高Ｔｃ相のみを単独でとりだす研究が
なされている。rConventional Technology Oxide superconductors consisting of bismuth, strontium, calcium, copper, and oxygen (hereinafter referred to as bismuth-based oxide superconductors) are known as high-temperature superconductors and have a low Tc phase of Tc ~ 80K. (The chemical formula is Bi.SrzcaCuzOs+xS
C-axis length of about 30 angstroms) and high Tc phase of Tc ~ 110K (Bi.SrzC a zc uso+o+w
, C-axis length of approximately 36 angstroms). Currently, research is being conducted to extract only this high Tc phase alone.
『従来の問題点』
しかしながら、通常の焼結法では高Ｔｃ相は低Ｔｃ相の
せいぜい５０バーセントしか得られず、しかも、その反
応は３〜７日間もかかり、反応温度も非常に微妙で再現
性が悪く、実用的でなかった．しかも、このようにして
得られる超伝導体は多結晶体で均一性にかけ、ビスマス
系酸化物超伝導体を超伝導デバイスには応用できなかっ
た。デバイスへの応用を考えると、単結晶は必要不可欠
である．しかしながら、従来、酸化物趨伝導体に結晶は
ほとんど得られなかった。``Conventional Problems'' However, with the usual sintering method, the high Tc phase can only be obtained at most 50 percent of the low Tc phase, and the reaction takes 3 to 7 days, and the reaction temperature is very delicate and reproducible. It was inconsiderate and impractical. Moreover, the superconductor obtained in this way is polycrystalline and lacks uniformity, making it impossible to apply bismuth-based oxide superconductors to superconducting devices. When considering device applications, single crystals are essential. However, until now, crystals have hardly been obtained in oxide-based conductors.
本発明は高Ｔｃ相を有しかつ大型の酸化物超伝導体単結
晶を得ることを目的としたものである．「発明の構成」
本発明は前記の目的を達成するために、酸化物超伝導体
原料融液からビスマス層状酸化物単結晶を種結晶として
用いて、引き上げ法によって酸化物超伝導体単結晶を作
製することとしたものである。The purpose of the present invention is to obtain a large oxide superconductor single crystal having a high Tc phase. "Structure of the Invention" In order to achieve the above object, the present invention uses a bismuth layered oxide single crystal as a seed crystal from an oxide superconductor raw material melt, and grows an oxide superconductor single crystal by a pulling method. This is what we decided to create.
本発明では、これらのビスマス層状酸化物のう？、その
Ｃ軸長が、高Ｔｃ相のそれに近いものの単結晶を種結晶
として用い、高Ｔｃ相の単結晶を得ようとするものであ
る．
大きな単結晶を作製する際、引上げ法の有利な点は単結
晶半導体製造法等でも実証されており、幸いなことにビ
スマス系酸化物超伝導体は溶融状態から冷却することに
よって得られるので引上げ法に適している。種結晶とし
ては（Ｂｉ．Ｏ■）（Ａ＠−ＩＢ＠０３■ｌ）であらわ
されるいわゆるビスマス層状酸化物を用いた．
ビスマス層状酸化物はビスマス系酸化物超伝導体とおな
しような構造をとり、格子定数についてもａ軸長、ｂ軸
長はほぼ等しく、種結晶として都合が好い。In the present invention, these bismuth layered oxide layers are used. , using a single crystal whose C-axis length is close to that of the high-Tc phase as a seed crystal to obtain a single crystal of the high-Tc phase. The advantage of the pulling method when producing large single crystals has been demonstrated in single crystal semiconductor manufacturing methods, etc. Fortunately, bismuth-based oxide superconductors can be obtained by cooling from a molten state, so pulling suitable for law. A so-called bismuth layered oxide represented by (Bi.O■) (A@-IB@03■l) was used as a seed crystal. Bismuth layered oxide has a structure similar to that of a bismuth-based oxide superconductor, and its lattice constants have approximately the same a-axis length and b-axis length, making it convenient as a seed crystal.
Ｃ軸長が高Ｔｃ相のそれに近いビスマス層状酸化物とし
ては、Ｂ ｉｍＴｉｓｏ＋ｚ （Ｃ軸長３２．８オング
ストローム） 、Ｃ ａ Ｂ ｉ４Ｔ ｉ ａｏＩｓ，
Ｓ ｒＢ ｉ ｓＴ ｉ ｓｏｂｓ、ＢａＢ ｉｎＴ
ｉ４０＋ｓ，ＰｂＢ ｉ４Ｔｉ４０＋ｓ、（以上Ｃ軸長
約４１〜４２オングストローム） 、Ｂ ｔｚ （Ｓｒ
＋−ｘＬａｄ ａｃｕ３ｏｙ（ｘ＝０．０５〜０．４、
ｙ＝８〜１２、Ｃ軸長約３６オングストローム）等があ
げられる．このような材料を種結晶として用いて、引上
げ法を試みた結果、ほぼ高Ｔｃ相のみからなる酸化物超
伝導体単結晶を得ることができた．
また本発明人は、Ｂ ｉ．ＬａＣａ，ＣｕｎＯ，（ｎ＝
１．２，３．以下ＢＬＣＣＯとよぶ）なるｌ連の複合酸
化物を発見し、それらの構造がビスマス系酸化物超伝導
体と同じであることを見出した。BimTiso+z (C-axis length 32.8 angstroms), C a B i4T i aoIs,
S rB i sT i sobs, BaB inT
i40+s, PbB i4Ti40+s, (C-axis length approximately 41 to 42 angstroms), B tz (Sr
+-xLad acu3oy (x=0.05~0.4,
y = 8 to 12, C-axis length approximately 36 angstroms), etc. As a result of attempting a pulling method using such a material as a seed crystal, we were able to obtain an oxide superconductor single crystal consisting almost exclusively of the high Tc phase. The inventor also has B i. LaCa, CunO, (n=
1.2,3. He discovered a series of complex oxides called BLCCO (hereinafter referred to as BLCCO) and found that their structure was the same as that of bismuth-based oxide superconductors.
これらの単結晶材料を、ビスマス系酸化物超伝導体の単
結晶成長の際の種結晶として用いることは非常に有効で
あった，ＢＬＣＣＯはビスマス系酸化物超伝導体と同じ
ような構造をとり、格子定数についてもａ軸長，ｂ軸長
はほぼ等しく、Ｃ軸長についても、ｎ＝１で２４オング
ストローム，ｎ＝２で３０オングストローム．ｎ＝３で
３６オングストロームとビスマス系酸化物超伝導体にお
けるｎ＝１．２．３と対応している。従って，ビスマス
系酸化物超伝導体のへテロエビタキシャル成長の種結晶
として都合が好い。本発明では，これ？のＢＬＣＣＯの
単結晶を種結晶として用い、引上げ法による単結晶成長
を試みた結果、２ｃｍ角のビスマス系酸化物超伝導体の
単結晶を得ることができたｑ
本発明による酸化物超伝導体はビスマス系に限らずその
他の酸化物超伝導体でも本発明の方法により作製するこ
とは可能である．以下、実施例によってより詳細に本発
明を説明する。It was very effective to use these single crystal materials as seed crystals for single crystal growth of bismuth-based oxide superconductors.BLCCO has a structure similar to that of bismuth-based oxide superconductors. Regarding the lattice constants, the a-axis length and the b-axis length are almost equal, and the c-axis length is 24 angstroms when n=1 and 30 angstroms when n=2. When n=3, it is 36 angstroms, which corresponds to n=1.2.3 in a bismuth-based oxide superconductor. Therefore, it is convenient as a seed crystal for the heteroepitaxial growth of bismuth-based oxide superconductors. This invention? As a result of trying to grow a single crystal by the pulling method using a single crystal of BLCCO as a seed crystal, we were able to obtain a 2 cm square single crystal of bismuth-based oxide superconductor q Oxide superconductor according to the present invention It is possible to fabricate not only bismuth-based superconductors but also other oxide superconductors using the method of the present invention. Hereinafter, the present invention will be explained in more detail with reference to Examples.
ｒ実施例１』
本実施例はＢ ｉ４Ｔｉｚｏ＋ｚ （Ｃ軸長３２．８オ
ングストローム）を種結晶として、ビスマス系酸化物超
伝導体単結晶を作製した場合を示す。Example 1 This example shows the case where a bismuth-based oxide superconductor single crystal was produced using B i4Tizo+z (C-axis length: 32.8 angstroms) as a seed crystal.
Ｂｉ４ＴｉｚＯ＋ｔ種結晶は二酸化ビスマス（Ｂｉ．ｏ
ｉ） 、二酸化チタン（ＴｉＯ■）粉末（純度はいずれ
も９９．９パーセント）を化学量論的組成比で混合した
後、それらの混合物をるつぼにいれ、空気中１２００″
Ｃで７日間保った後、生成させた反応物を粉砕すること
により得た。得られた種結晶の大きさは３ミリ×３ミリ
×１ミリ程度であった。Bi4TizO+t seed crystal is bismuth dioxide (Bi.o
i) After mixing titanium dioxide (TiO■) powders (all purity 99.9%) in a stoichiometric composition ratio, the mixture was placed in a crucible and heated at 1200'' in air.
After keeping at C for 7 days, the resulting reaction product was pulverized. The size of the obtained seed crystal was approximately 3 mm x 3 mm x 1 mm.
ビスマス系酸化物超伝導体単結晶の原料は、三酸化ビス
マス（Ｂ ｉ ｇｏ３） 、炭酸ストロンチウム（Ｓｒ
ＣＯ，）、炭酸カルシウム（ＣａＣＯｓ）、酸化銅（Ｃ
ｕＯ）粉末（いずれも純度９９．９パーセント）で、こ
れらの原料粉末は、Ｂｉ：Ｓｒ：Ｃａ：Ｃｕ＝４：２：
２：３ （モル比）の割合で混合された．原料はその融
点を下げるために適当な融剤を加えられられたり、蒸発
しやすい成分については、蒸発による損失を補うために
余分に加えられることもある．
これらの混合粉末は、空気中８００゜Ｃで１２時間焼成
した後、るつぼにいれられ、空気中８９０℃に加熱され
、溶融された．種結晶は第１図に示すように融液の液面
にそのＣ軸が平行になるように、液面に接触するように
置かれた．第１図において１アルミナるつぼ、２は単結
晶原料融液、３は種結晶、４は支持棒、５は石英管、６
は高周波コイル、７は熱電対をそれぞれ示す．
種結晶は１時間に５ミリの速度で引き上げられた．得ら
れたビスマス系酸化物超伝導体の単結晶の大きさは５ミ
リ×３０ミリ×０．５ミリの板状であった。The raw materials for bismuth-based oxide superconductor single crystals are bismuth trioxide (B i go3), strontium carbonate (Sr
CO, ), calcium carbonate (CaCOs), copper oxide (C
uO) powder (all purity 99.9%), these raw material powders are Bi:Sr:Ca:Cu=4:2:
They were mixed at a ratio of 2:3 (molar ratio). Appropriate fluxing agents may be added to raw materials to lower their melting points, and for components that easily evaporate, excess amounts may be added to compensate for losses due to evaporation. These mixed powders were calcined in air at 800°C for 12 hours, then placed in a crucible and heated to 890°C in air to melt. The seed crystal was placed in contact with the melt surface, with its C axis parallel to the melt surface, as shown in Figure 1. In Figure 1, 1 is an alumina crucible, 2 is a single crystal raw material melt, 3 is a seed crystal, 4 is a support rod, 5 is a quartz tube, and 6
indicates a high-frequency coil, and 7 indicates a thermocouple. The seed crystal was pulled at a rate of 5 mm per hour. The resulting single crystal of the bismuth-based oxide superconductor had a plate shape of 5 mm x 30 mm x 0.5 mm.
得られた単結晶はＸ線回折法より高Ｔｃ相から成ってい
ることが認められた。また第２図に示されるようにこの
膜は１１０Ｋでゼロ抵抗を示し、液体窒素温度での臨界
電流密度は、約１０万Ａ／ｃｍ”であった．
ｒ実施例２』
本実施例ではＢ ｉ．Ｌａｃａ．ｃｕ．ｏ，（ｎ＝２，
ｃ軸長３０オングストローム）を種結晶として、ビスマ
ス系酸化物超伝導体単結晶を作製した場合を示す．
Ｂｉ．ＬａＣａ．ＣｕｚＯ，種結晶は二酸化ビスマス（
Ｂ ｉ．ｏ．），酸化ランタン（ＬａｇＯ＊）、炭酸カ
ルシウム（ＣａＣＯ．），酸化銅（ＣｕＯ）粉末（純度
はいずれも９９．９パーセント）を２：１：１：２（モ
ル比）の割合で混合したものをるつぼにいれ、空気中１
０００℃で１時間保った後、毎時１０℃で冷却し、生成
物を機械的に粉砕して拾い出したもので大きさは３ミリ
×３ミリ×１ミリ程度であった．
ビスマス系酸化物超伝導体単結晶の原料は、二酸化ヒス
マス（Ｂ ｉ ｇｏｓ） ． 炭Ｍストロンチウム（Ｓ
ｒＣＯｉ），炭酸カルシウム（ Ｃ ａ Ｃ Ｏｓ）、
酸化銅（Ｃｕｂ）粉末（いずれも純度９９．９パーセン
ト）で、これらの原料粉末は、Ｂｉ：Ｓｒ：Ｃａ：Ｃｕ
＝１：１：１：３ （モル比）の割合で混合された．こ
れらの混合粉末は、空気中８００゜Ｃで１２時間焼成し
た後、るつぼに入れ、空気中８９０℃に加熱し、溶融さ
せた。種結晶は第１図に示すように融液の液面にそのＣ
軸が平行になるように、液面に接触するように置かれた
種結晶は１！寺間に５ミリの速度で引き上げられた．得
られたビスマス系酸化物超伝導体の単結晶の大きさは、
２０ミリ×２０ミリ×０．５ミリの板状であった．
Ｘ線回折法から、単結晶は中Ｔｃ相から成っていること
が認められ、また第３図に示されるようにこの単結晶超
伝導材料は８２Ｋでゼロ抵抗を示し，液体窒素温度での
臨界電流密度は，約１万Ａ／ｃｍ”であった・
ｒ実施例３』
化学弐Ｂ ｉｚ （Ｓｒ＋−ｘＬａｘ） ４ｃｕｓｏｙ
（Ｘ＝０．０５〜０．４、ｙｘ３〜１２）で表される
酸化物は、構造がビスマス系超伝導体の高Ｔｃ相と同じ
（ａ軸長５．４オングストローム、Ｃ軸長３６オングス
トローム）であるが、キャリアー濃度が小さいため、超
伝導性を示さない．このＢｉ！（Ｓｒ＋−ｘＬａｘ）ａ
Ｃｕ２ｏＶを単結晶成長の種結晶とし、ビスマス系超伝
導体の高Ｔｃ相を成長させた，Ｂ ｉｔ （Ｓｒ＋−ｍ
Ｌａｍ） ４ｃｕ２ｏｒ単結晶はＣｕＯを融剤とするフ
ラックス法によって作製された．原料としてはＢｉ．０
３、ＳｒＣＯ．、Ｌａ．０，、ＣｕＯ （純度はすべて
９９．９％）の粉末を用い、Ｂｉ：Ｓｒ：Ｌａ：Ｃｕ＝
２：３．５：０．５：６（モル比）で混合し、アルミナ
るつぼに充填し、空気中１ ０ ０ ０ ’Ｃで５時間
反応させた後８００゜Ｃまで１０゜Ｃ／時で徐冷して得
られた。It was confirmed by X-ray diffraction that the obtained single crystal consisted of a high Tc phase. Furthermore, as shown in Fig. 2, this film showed zero resistance at 110 K, and the critical current density at liquid nitrogen temperature was about 100,000 A/cm. i.Laca.cu.o, (n=2,
The case where a bismuth-based oxide superconductor single crystal was prepared using a seed crystal with a c-axis length of 30 angstroms is shown. Bi. LaCa. CuzO, seed crystal is bismuth dioxide (
B i. o. ), lanthanum oxide (LagO*), calcium carbonate (CaCO.), and copper oxide (CuO) powder (all purity 99.9%) mixed in a ratio of 2:1:1:2 (molar ratio). put in a melting pot, 1 in the air
After being kept at 000°C for 1 hour, it was cooled at 10°C per hour, and the product was mechanically crushed and collected, and the size was about 3 mm x 3 mm x 1 mm. The raw material for the bismuth-based oxide superconductor single crystal is hismuth dioxide (B i gos). Charcoal M Strontium (S
rCOi), calcium carbonate (C a COs),
Copper oxide (Cub) powder (all purity 99.9%), these raw material powders are Bi:Sr:Ca:Cu
=1:1:1:3 (molar ratio). These mixed powders were calcined in air at 800°C for 12 hours, then placed in a crucible and heated in air to 890°C to melt. The seed crystal is placed on the surface of the melt as shown in Figure 1.
A seed crystal placed in contact with the liquid surface with its axes parallel is 1! It was pulled up to Terama at a speed of 5 mm. The size of the single crystal of the obtained bismuth-based oxide superconductor is
It was plate-shaped, measuring 20 mm x 20 mm x 0.5 mm. From the X-ray diffraction method, it was confirmed that the single crystal consists of a medium Tc phase, and as shown in Figure 3, this single crystal superconducting material exhibits zero resistance at 82 K and a critical temperature at liquid nitrogen temperature. The current density was approximately 10,000 A/cm''.
The oxide represented by ), but because the carrier concentration is small, it does not exhibit superconductivity. This Bi! (Sr+-xLax)a
B it (Sr+-m
Lam) 4cu2or single crystal was prepared by a flux method using CuO as a flux. As a raw material, Bi. 0
3, SrCO. , La. Using powder of 0, CuO (all purity 99.9%), Bi:Sr:La:Cu=
2:3.5:0.5:6 (molar ratio), filled into an alumina crucible, reacted in air at 1000'C for 5 hours, and then heated to 800°C at 10°C/hour. Obtained by slow cooling.
そして、るつぼ内部の溶融凝固物を機械的に破壊し、単
結晶を拾いあげた．このようにして得られた単結晶は大
きなもので５ｍｍＸ５ｍｍＸ０．５ｍｍの板状であった
。ビスマス系酸化物超伝導体単結晶はこのＢ ｉｚ （
Ｓ ｒ＋−ｘＬａｘ） ４ｃｕ＝０，単結晶を種結晶と
して引き上げ法によって作製された．Ｓ結晶作製の条件
等は、？実施例１』と同様である．得られたビスマス系
酸化物超伝導体単結晶の大きさは５ｍｍＸ５０ｍｍＸ０
．５ｍｍの板状であり、Ｘ線回折法から単結晶は高Ｔｃ
相から成っていることが認められた。また抵抗率測定か
らゼロ抵抗温度１０６Ｋが得られた。Then, the molten solidified material inside the crucible was mechanically destroyed and the single crystal was picked up. The single crystal thus obtained was large and had a plate shape of 5 mm x 5 mm x 0.5 mm. The bismuth-based oxide superconductor single crystal is this B iz (
Sr+-xLax) 4cu=0, produced by the pulling method using a single crystal as a seed crystal. What are the conditions for producing S crystals? This is the same as in Example 1. The size of the obtained bismuth-based oxide superconductor single crystal is 5 mm x 50 mm x 0.
．． It has a plate shape of 5 mm, and the single crystal has a high Tc according to X-ray diffraction method.
It was recognized that it consists of phases. Also, a zero resistance temperature of 106K was obtained from resistivity measurements.
ｒ効果』
本発明によればこれらのビスマス層状酸化物のうち、そ
のＣ軸長が、高Ｔｃ相のそれに近いものの単結晶を種結
晶として用いたために、高Ｔｃ相の単結晶が得られると
同時に大型の単結晶を得ることができた．この単結晶を
用いて、デバイスを作製することが可能であり、本発明
は工業上極めて有益である．According to the present invention, among these bismuth layered oxides, a single crystal with a C-axis length close to that of the high-Tc phase is used as a seed crystal, so that a single crystal with a high-Tc phase can be obtained. At the same time, we were able to obtain large single crystals. It is possible to fabricate devices using this single crystal, and the present invention is extremely useful industrially.
第１図は引き上げ法による結晶成長の様子を示？た図。
第２図はＢｉ４Ｔｉ３０＋■単結晶を種結晶として得ら
れたビスマス系酸化物超伝導体単結晶の抵抗一温度曲線
を示す。
第３図はＢＬＣＯ単結晶を種結晶として得られイカ１
たビスマス系酸化物超電導体単結晶の抵抗一温度曲線を
示す。
アルミナるつぼ
単結晶原料融液
種結晶
支持棒
石英管
高周波コイル
熱電対Figure 1 shows the state of crystal growth by the pulling method? Figure. FIG. 2 shows a resistance-temperature curve of a bismuth-based oxide superconductor single crystal obtained using a Bi4Ti30+■ single crystal as a seed crystal. FIG. 3 shows a resistance-temperature curve of a bismuth-based oxide superconductor single crystal obtained using a BLCO single crystal as a seed crystal. Alumina crucible single crystal raw material melt seed crystal support rod quartz tube high frequency coil thermocouple
Claims (1)
酸化物超伝導体原料融液から引き上げ法により、酸化物
超伝導体単結晶を作製することを特徴とする酸化物超伝
導体の作製方法。 ２、特許請求の範囲第１項において酸化物超伝導体は、
ビスマス層状酸化物であることを特徴とする酸化物超伝
導体の作製方法 ３、特許請求の範囲第１項および第２項において酸化物
超伝導体は、ビスマス、ストロンチウム、カルシウム、
銅、酸素から成り、その化学式はＢｉ＿２Ｓｒ＿２Ｃａ
＿ｎ＿−＿１Ｃｕ＿ｎＯ＿ｙ（ｎ＝１、２、３）で表さ
れ、その臨界温度が、液体窒素の沸点以上であることを
特徴とする酸化物超伝導体の作製方法。 ４、特許請求の範囲第１項において、種結晶として用い
られるビスマス層状酸化物は、そのｃ軸長が酸化物超伝
導体のｃ軸長に近いものであることを特徴とする酸化物
超伝導体の作製方法。[Claims] 1. Using a bismuth layered oxide single crystal as a seed crystal,
A method for producing an oxide superconductor, comprising producing an oxide superconductor single crystal by a pulling method from an oxide superconductor raw material melt. 2. In claim 1, the oxide superconductor is:
In method 3 for producing an oxide superconductor characterized in that it is a bismuth layered oxide, the oxide superconductor in claims 1 and 2 includes bismuth, strontium, calcium,
Consisting of copper and oxygen, its chemical formula is Bi_2Sr_2Ca
A method for producing an oxide superconductor represented by _n_-_1Cu_nO_y (n=1, 2, 3), characterized in that its critical temperature is equal to or higher than the boiling point of liquid nitrogen. 4. In claim 1, the bismuth layered oxide used as the seed crystal is an oxide superconductor characterized in that its c-axis length is close to the c-axis length of the oxide superconductor. How to create the body.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1006375A JPH02229787A (en) | 1988-07-05 | 1989-01-13 | Production of oxide superconductor |
| US07/372,473 US5032571A (en) | 1988-07-05 | 1989-06-28 | Method of manufacturing oxide superconducting materials |
| EP89306837A EP0350294A3 (en) | 1988-07-05 | 1989-07-05 | Method of manufacturing superconducting oxide materials |
| US07/912,663 US5268060A (en) | 1988-07-05 | 1992-07-14 | Method of manufacturing oxide superconducting materials |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63-167059 | 1988-07-05 | ||
| JP16705988 | 1988-07-05 | ||
| JP63-277711 | 1988-11-02 | ||
| JP1006375A JPH02229787A (en) | 1988-07-05 | 1989-01-13 | Production of oxide superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02229787A true JPH02229787A (en) | 1990-09-12 |
Family
ID=26340496
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1006375A Pending JPH02229787A (en) | 1988-07-05 | 1989-01-13 | Production of oxide superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02229787A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06172095A (en) * | 1992-12-07 | 1994-06-21 | Agency Of Ind Science & Technol | Production of bi2@(3754/24)sr, ca)3cu2o8 single crystal by solution pulling-up method |
-
1989
- 1989-01-13 JP JP1006375A patent/JPH02229787A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06172095A (en) * | 1992-12-07 | 1994-06-21 | Agency Of Ind Science & Technol | Production of bi2@(3754/24)sr, ca)3cu2o8 single crystal by solution pulling-up method |
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