JPH01305897A - Preparation of single crystal of oxide superconductor - Google Patents
Preparation of single crystal of oxide superconductorInfo
- Publication number
- JPH01305897A JPH01305897A JP63137084A JP13708488A JPH01305897A JP H01305897 A JPH01305897 A JP H01305897A JP 63137084 A JP63137084 A JP 63137084A JP 13708488 A JP13708488 A JP 13708488A JP H01305897 A JPH01305897 A JP H01305897A
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- barium
- copper
- oxide superconductor
- starting materials
- 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
- 239000013078 crystal Substances 0.000 title claims abstract description 33
- 239000002887 superconductor Substances 0.000 title claims abstract description 13
- IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Inorganic materials [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000000203 mixture Substances 0.000 claims abstract description 13
- 239000007858 starting material Substances 0.000 claims abstract description 11
- 229910052788 barium Inorganic materials 0.000 claims abstract description 9
- 229910052802 copper Inorganic materials 0.000 claims abstract description 9
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 7
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 claims description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 11
- 239000001301 oxygen Substances 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 8
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 8
- 239000010949 copper Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 claims description 6
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 3
- 239000011148 porous material Substances 0.000 abstract description 15
- 238000005259 measurement Methods 0.000 abstract description 2
- 230000000704 physical effect Effects 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract description 2
- 229910003098 YBa2Cu3O7−x Inorganic materials 0.000 abstract 1
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 11
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 8
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 239000005751 Copper oxide Substances 0.000 description 4
- 238000000137 annealing Methods 0.000 description 4
- 229910000431 copper oxide Inorganic materials 0.000 description 4
- 239000001569 carbon dioxide Substances 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 238000007716 flux method Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000010583 slow cooling Methods 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【発明の詳細な説明】
「発明の利用分野」
本発明は酸化物高温超伝導体のＹＢａｚＣｕ３０ｔ−ｘ
（以下ＹＢＣＯと略す）ノ単結晶の作製方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to an oxide high temperature superconductor YBazCu30t-x
(hereinafter abbreviated as YBCO) single crystal manufacturing method.
「従来の技術」
臨界温度（Ｔｃ）が９０Ｋにも達する高温超伝導体とし
てＹＢＣＯが発見されるやいなやその単結晶が作製され
た。"Prior Art" Immediately after YBCO was discovered as a high-temperature superconductor with a critical temperature (Tc) of 90K, single crystals thereof were produced.
この単結晶は、主として、出発材料に過剰の酸化銅や炭
酸バリウムを加えそれらを融剤（フラックス）として混
合物の融点を下げ、結晶を成長させる、いわゆるフラツ
クス性によって作製されている。This single crystal is mainly produced by a so-called flux process in which an excess of copper oxide or barium carbonate is added to the starting material and used as a flux to lower the melting point of the mixture and grow the crystal.
通常の半導体等の作製に用いられる単結晶はチョコラル
スキー法等により作製されている。しかしながらＹＢＣ
Ｏの単結晶の作製にチョコラルスキー法は使われていな
い、その理由は、ＹＢＣＯは１０００°Ｃ以上では非超
伝導体相（ＹｔＢａ Ｃｕ Ｏｓ）になってしまうため
、融液からの直接成長ができないためである。Single crystals used in the production of ordinary semiconductors are produced by the Czochralski method or the like. However, YBC
The Czochralski method is not used to produce O single crystals because YBCO becomes a non-superconducting phase (YtBa Cu Os) at temperatures above 1000°C, so direct growth from a melt is not possible. This is because it cannot be done.
一方フラックス法によるＹＢＣＯ単結晶の成長では、１
１．Ｋａｔａｙｍａ−Ｙｏｓｈｉｄａ ｅｔ ａｌ（Ｊ
ｐｎｊ。On the other hand, in the growth of YBCO single crystal by flux method, 1
1. Katayama-Yoshida et al (J
pnj.
Ａｐｐｌ、Ｐｈｙｓ、２６（１９８７）Ｌ２００７）が
、混合物内にできる空孔において比較的大きなＹＢＣＯ
単結晶（５ミリ角程度）が得られると報告している。Appl, Phys, 26 (1987) L2007), YBCO is relatively large in the pores formed in the mixture.
It is reported that a single crystal (about 5 mm square) can be obtained.
「従来の問題点Ｊ
Ｈ，Ｋａｔａｙｎｉａ−Ｙｏｓｈｉｄａ ｅｔ ａｌの
報告は、出発材料として酸化イツトリウム、炭酸バリウ
ム、酸化銅を用い、酸化銅を過剰に加えるＣｕＯフラッ
クス法を採用して、これらの混合物を高温で反応させる
際、炭酸バリウムや酸化銅が分解して生じた二酸化炭素
や酸素が試料内に空孔を形成し、この空孔内でのみ大き
な単結晶が得られるというものである。"Conventional Problems The report by J. H., Kataynia-Yoshida et al. used yttrium oxide, barium carbonate, and copper oxide as starting materials, adopted the CuO flux method in which copper oxide was added in excess, and heated these mixtures to high temperatures. During the reaction, carbon dioxide and oxygen produced by the decomposition of barium carbonate and copper oxide form pores within the sample, and large single crystals can only be obtained within these pores.
しかしながら、上記ＣｕＯフラックス法においては空孔
の形成は十分なものではなく、できる空孔の大きさも限
られてしまうという問題があった。なぜならば、前記の
出発材料では試料の融解と二酸化炭素等の発生がほぼ同
じ温度でおこるため、もしくは試料の融解する温度より
二酸化炭素の発生する温度の方が低いためである。However, the CuO flux method described above has the problem that the formation of pores is not sufficient and the size of the pores that can be formed is also limited. This is because, in the above starting materials, the melting of the sample and the generation of carbon dioxide, etc. occur at approximately the same temperature, or the temperature at which carbon dioxide is generated is lower than the temperature at which the sample melts.
本発明はＹＢＣＯ単結晶作製の際、混合物内にできる空
孔を大きなものとし、大きなＹＢＣＯ単結晶を得ること
を目的としたものである。The purpose of the present invention is to increase the size of pores formed in a mixture during production of a YBCO single crystal, thereby obtaining a large YBCO single crystal.
「問題を解決するための手段」
本発明は空孔を形成するのに必要なガスの発生する温度
よりも試料の軟化する温度の方が低ければより大きな空
孔が形成されることを考えこの条件を満足させるために
、炭酸バリウムの代わりに硝酸バリウムを用いることと
した。そのために、イツトリウム、バリウム、銅、酸素
からなる酸化物超伝導体のＹＢａｚｃｕ３０ｖ−ｘ単結
晶を得る際に、出発材料として酸化イツトリウム（ｙ、
ｏ、） 、硝酸バリウム（Ｂａ（ＮＯｌ）２）、酸化１
ｉ（ＣｕＯ）を用いることとしたものである。"Means for Solving the Problem" The present invention takes into consideration that larger pores will be formed if the softening temperature of the sample is lower than the temperature at which the gas necessary to form pores is generated. In order to satisfy the conditions, it was decided to use barium nitrate instead of barium carbonate. For this purpose, when obtaining a YBazcu30v-x single crystal of an oxide superconductor consisting of yttrium, barium, copper, and oxygen, yttrium oxide (y,
o, ), barium nitrate (Ba(NOl)2), oxide 1
i(CuO) was used.
化学大辞典（井守出版）によれば、硝酸バリウムは融点
が ５９２°Ｃで、それより高温では分解してガス（主
として二酸化窒素）を発生する。したがって、試料が軟
化してからガスが発生し、空孔を形成するのには理想的
である。実際、硝酸バリウムを用いたほうが、炭酸バリ
ウムを用いるよりもはるかに大きな空孔（内径１０ミリ
以上）が得られた。また、この空孔内に成長した結晶も
最大で１０ミリ角（厚さ約０．５ミリ）のものが得られ
た。以下、実施例を示し、さらに本発明を説明する。According to the Chemical Encyclopedia (Imori Publishing), barium nitrate has a melting point of 592°C, and at higher temperatures it decomposes and generates gas (mainly nitrogen dioxide). Therefore, gas is generated after the sample softens, which is ideal for forming pores. In fact, much larger pores (inner diameter of 10 mm or more) were obtained by using barium nitrate than by using barium carbonate. Furthermore, crystals grown within the pores were up to 10 mm square (approximately 0.5 mm thick). EXAMPLES Hereinafter, the present invention will be further explained by showing examples.
「実施例１」
原料として酸化イツトリウム、硝酸バリウム、酸化銅粉
末（いずれも、純度は９９．９パーセント）を用いた。"Example 1" Yttrium oxide, barium nitrate, and copper oxide powder (all with a purity of 99.9%) were used as raw materials.
これらの粉末を、イツトリウム、バリウム、銅のモル比
がそれぞれ１：４：６となるようにはかりとり、十分に
混合した。この混合物約１０グラムをアルミするつぼに
いれ、第１図の温度プログラムに示す温度条件で、酸素
気流中で焼成した。These powders were weighed and thoroughly mixed so that the molar ratio of yttrium, barium, and copper was 1:4:6, respectively. Approximately 10 grams of this mixture was placed in an aluminum crucible and fired in an oxygen stream under the temperature conditions shown in the temperature program shown in FIG.
混合物内には内径約１５ミリの空孔ができていた。空孔
内には５ミリ角でいどのＹＢ Ｃ０単結晶が１０枚程度
できていた。さらにこれらのＹＢＣＯ単結晶が超伝導性
を持つようにするため、酸素雰囲気９００°Ｃでのアニ
ールおよびその後の徐冷（冷却速度６０°Ｃ／時）を行
なった。その結果第２図に示すような超伝導性を示すＹ
ＢＣＯ単結晶を得ることができた。Pores with an inner diameter of approximately 15 mm were formed within the mixture. Approximately 10 YB CO single crystals of 5 mm square were formed inside the hole. Furthermore, in order to make these YBCO single crystals have superconductivity, annealing in an oxygen atmosphere at 900°C and subsequent slow cooling (cooling rate of 60°C/hour) were performed. As a result, Y exhibits superconductivity as shown in Figure 2.
A BCO single crystal could be obtained.
「実施例２ｊ
原料として酸化イツトリウム、硝酸バリウム、酸化銅粉
末（いずれも、純度は９９．９パーセント）を用いた。"Example 2j Yttrium oxide, barium nitrate, and copper oxide powder (all with a purity of 99.9%) were used as raw materials.
これらの粉末を、イツトリウム、バリウム、銅のモル比
がそれぞれ１：４：６となるようにはかりとり、十分に
混合した。この混合物約１０グラムをアルミするつぼに
いれ、酸素雰囲気１１５０”Ｃで１時間焼成したあと室
温まで急冷した。その後、再び、酸素雰囲気中９７０°
Ｃに加熱して７日間焼成した。試料内には内径約１５ミ
リの空孔ができていた。空孔内には５ミリ角ていどのＹ
ＢＣＯ単結晶が１０枚程度できていた。さらにこれらの
ＹＢＣｏ単結晶が超伝導性を持つようにするため酸素雰
囲気９００°Ｃでのアニールおよびその後の徐冷（冷却
速度６０°Ｃ／時）を行なった。その結果第３図に示す
ような超伝導性を示すＹＢＣＯ単結晶を得ることができ
た。These powders were weighed and thoroughly mixed so that the molar ratio of yttrium, barium, and copper was 1:4:6, respectively. Approximately 10 grams of this mixture was placed in an aluminum crucible, baked in an oxygen atmosphere at 1150"C for 1 hour, and then rapidly cooled to room temperature. Thereafter, it was heated again in an oxygen atmosphere at 970"C.
C. and baked for 7 days. A hole with an inner diameter of approximately 15 mm was formed within the sample. There is a 5 mm square Y inside the hole.
About 10 BCO single crystals were formed. Further, in order to make these YBCo single crystals have superconductivity, annealing in an oxygen atmosphere at 900°C and subsequent slow cooling (cooling rate of 60°C/hour) were performed. As a result, a YBCO single crystal exhibiting superconductivity as shown in FIG. 3 could be obtained.
「効果」
本発明よって、出発材料として酸化イツトリウム（Ｙ２
Ｏ，）、硝酸バリウム（Ｂａ（ＮＯ８）ｔ）、酸化銅（
Ｃｕｂ）を用いることによってＹＢＣＯ単結晶が成長す
るために必要な空孔を上記の出発材料混合物中に確実に
形成されることができ、その結果比較的大きなＹＢＣＯ
単結晶を確実にしかも効率よく得られるようになった。"Effect" According to the present invention, yttrium oxide (Y2
O,), barium nitrate (Ba(NO8)t), copper oxide (
By using the above-mentioned starting material mixture, the holes necessary for the growth of YBCO single crystals can be reliably formed in the above starting material mixture, resulting in a relatively large YBCO
Single crystals can now be obtained reliably and efficiently.
単結晶は精密な物性測定に必要であるばかりでなく、超
伝導体デバイス等の作製にも不可欠なものと考えられる
。Single crystals are not only necessary for precise physical property measurements, but are also considered essential for the production of superconductor devices.
したがって、本発明は工業上有益なものである。Therefore, the present invention is industrially useful.
第１図は単結晶製造の温度プログラムを示す図。
（ａ）は加熱速度３００°Ｃ／時の領域（ｂ）は等温時
間２時間の領域
（ｃ）は冷却速度６°Ｃ／時の領域
（ｄ）は冷却速度３００°Ｃ／時の領域をそれぞれ示し
ている
第２図及び第３図は単結晶の抵抗−温度曲線の関係を示
す図。
（ｅ）は酸素アニール前
（ｆ）は酸素アニール後を示している。FIG. 1 is a diagram showing a temperature program for producing a single crystal. (a) is a heating rate of 300°C/hour (b) is an isothermal time of 2 hours (c) is a cooling rate of 6°C/hour (d) is a cooling rate of 300°C/hour FIGS. 2 and 3, respectively, are diagrams showing the relationship between the resistance-temperature curve of a single crystal. (e) shows before oxygen annealing and (f) shows after oxygen annealing.
Claims (4)
超伝導体のＹＢａ＿２Ｃｕ＿３Ｏ＿７＿−＿ｘ単結晶を
得るために、出発材料として酸化イットリウム（Ｙ＿２
Ｏ＿３）、硝酸バリウム（Ｂａ（ＮＯ＿３）＿２）、酸
化銅（ＣｕＯ）を用いることを特徴とする酸化物超伝導
体単結晶の作製方法。1. Yttrium oxide (Y_2
A method for producing an oxide superconductor single crystal, characterized in that it uses barium nitrate (Ba(NO_3)_2), and copper oxide (CuO).
３Ｏ＿７＿−＿ｘの化学量論的組成（すなわち、モル比
で、イットリウム：バリウム：銅＝１：２：３）に比べ
、バリウムと銅が過剰になるよう出発材料を混合し、こ
の混合物を空気中もしくは酸素中１０００℃〜１２５０
℃（望ましくは１１００〜１２００℃）で加熱し、その
後、毎時１０℃以下の冷却速度で極めてゆっくりと８０
０〜９００℃まで冷却することを特徴とする酸化物超伝
導体単結晶の作製方法。2. In claim 1, YBa_2Cu_
The starting materials are mixed with an excess of barium and copper compared to the stoichiometric composition of 3O_7_-_x (i.e., yttrium:barium:copper = 1:2:3 in molar ratio), and the mixture is heated in air. Or 1000℃~1250℃ in oxygen
°C (preferably 1100-1200 °C) and then very slowly at a cooling rate of 10 °C or less per hour to 80 °C.
A method for producing an oxide superconductor single crystal, which comprises cooling to 0 to 900°C.
３Ｏ＿７＿−＿ｘＹＢＣＯの化学量論的組成（すなわち
、モル比で、イットリウム：バリウム：銅＝１：２：３
）に比べ、バリウムと銅が過剰になるよう出発材料を混
合し、この混合物を空気中もしくは酸素中１０００℃〜
１２５０℃（望ましくは１１００〜１２００℃）で数時
間加熱し、その後、室温まで急冷し、さらに、再び、空
気中もしくは酸素中９００〜１０００℃で１００時間以
上加熱することによって単結晶を成長させることを特徴
とする酸化物超伝導体単結晶の作製方法。3. In claim 1, YBa_2Cu_
3O_7_-_xYBCO stoichiometric composition (i.e., in molar ratio, yttrium: barium: copper = 1:2:3
), the starting materials are mixed so that barium and copper are in excess compared to
Growing a single crystal by heating at 1250°C (preferably 1100 to 1200°C) for several hours, then rapidly cooling to room temperature, and heating again at 900 to 1000°C in air or oxygen for 100 hours or more. A method for producing an oxide superconductor single crystal characterized by:
て出発材料の混合比（モル比）はイットリウムを１とし
たとき、バリウムが２〜９、銅が４〜１２の値をとるこ
とを特徴とする酸化物超伝導体単結晶の作製方法。4. In claim 1, 2, or 3, the mixing ratio (molar ratio) of the starting materials is such that when yttrium is 1, barium is 2 to 9, and copper is 4 to 12. Characteristic method for producing oxide superconductor single crystals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137084A JPH01305897A (en) | 1988-06-02 | 1988-06-02 | Preparation of single crystal of oxide superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63137084A JPH01305897A (en) | 1988-06-02 | 1988-06-02 | Preparation of single crystal of oxide superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01305897A true JPH01305897A (en) | 1989-12-11 |
Family
ID=15190515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63137084A Pending JPH01305897A (en) | 1988-06-02 | 1988-06-02 | Preparation of single crystal of oxide superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01305897A (en) |
-
1988
- 1988-06-02 JP JP63137084A patent/JPH01305897A/en active Pending
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