JPH08198700A - Production of thin film of thallium-containing superconductor - Google Patents
Production of thin film of thallium-containing superconductorInfo
- Publication number
- JPH08198700A JPH08198700A JP7023342A JP2334295A JPH08198700A JP H08198700 A JPH08198700 A JP H08198700A JP 7023342 A JP7023342 A JP 7023342A JP 2334295 A JP2334295 A JP 2334295A JP H08198700 A JPH08198700 A JP H08198700A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- flux
- thallium
- substrate
- growth
- 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
- 239000010409 thin film Substances 0.000 title claims abstract description 38
- 239000002887 superconductor Substances 0.000 title claims abstract description 28
- 229910052716 thallium Inorganic materials 0.000 title claims description 14
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 title claims description 14
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 230000004907 flux Effects 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 19
- 239000013078 crystal Substances 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 18
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 10
- 239000000843 powder Substances 0.000 claims abstract description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 239000011780 sodium chloride Substances 0.000 claims abstract description 5
- 238000011282 treatment Methods 0.000 claims abstract description 5
- 239000011261 inert gas Substances 0.000 claims abstract 2
- 238000002844 melting Methods 0.000 claims description 9
- 230000008018 melting Effects 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 3
- 239000004020 conductor Substances 0.000 claims 1
- 229910000601 superalloy Inorganic materials 0.000 claims 1
- 238000010583 slow cooling Methods 0.000 abstract 1
- 239000010408 film Substances 0.000 description 11
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 10
- 239000000463 material Substances 0.000 description 8
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229910052737 gold Inorganic materials 0.000 description 5
- 239000010931 gold Substances 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000001947 vapour-phase growth Methods 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- 229910002367 SrTiO Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000000608 laser ablation Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000007704 transition Effects 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
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Containers, Films, And Cooling For Superconductive Devices (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、各種の超伝導応用装置
や超伝導素子に用いられるＴｌ系酸化物超伝導体薄膜の
製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a Tl-based oxide superconductor thin film used in various superconducting devices and superconducting devices.
【０００２】[0002]
【従来の技術】金属、合金系超伝導体や化合物超伝導体
は、ジョセフソン素子や超伝導マグネット線材、磁気シ
ールド材料として、既に広く利用されている。これらの
実用化応用装置における冷却手段としては、現在なお液
体ヘリウムが主流となっている。使用している超伝導材
料の超伝導転移温度（Ｔｃ）が上昇し、液体ヘリウムの
代わりに安価な液体窒素や冷凍機が使えるようになれ
ば、応用装置の適用範囲が飛躍的に増えると期待されて
いる。2. Description of the Related Art Metal and alloy type superconductors and compound superconductors are already widely used as Josephson devices, superconducting magnet wire rods and magnetic shield materials. Liquid helium is still the mainstream as the cooling means in these practical application devices. If the superconducting transition temperature (Tc) of the superconducting material being used rises and cheap liquid nitrogen or refrigerator can be used instead of liquid helium, it is expected that the applicable range of applied equipment will increase dramatically. Has been done.
【０００３】１９８６年にＬａ−Ｂａ−Ｃｕ−Ｏ系で高
温超伝導体が発見されて以来、多くの研究者により銅酸
化物超伝導体についての研究が精力的に進められ、様々
な材料についての発表が行われてきた。その中でも、現
在最も高いＴｃが報告されている物質の一つにタリウム
（Ｔｌ）系と称される一群の銅酸化物がある。それゆえ
に、Ｔｌ系超伝導体は酸化物超伝導体の応用を考えるう
えで、最も重要な物質であるということができる。Since the discovery of high-temperature superconductors in the La-Ba-Cu-O system in 1986, many researchers have energetically advanced research on copper oxide superconductors, and have investigated various materials. Has been announced. Among them, one of the substances for which the highest Tc is currently reported is a group of copper oxides called thallium (Tl) series. Therefore, it can be said that the Tl-based superconductor is the most important substance in considering the application of the oxide superconductor.
【０００４】酸化物超伝導体のエレクトロニクスへの応
用において欠かすことができないのが良質な単結晶薄膜
を製造する技術である。イットリウム（Ｙ）系やビスマ
ス（Ｂｉ）系の酸化物超伝導体に関しては、スパッタリ
ングやレーザーアブレーションなどの手法により、かな
り高品位の膜が得られるようになってきたが、タリウム
系に関しては未だ良質な膜は得られていない。Indispensable for the application of oxide superconductors to electronics is a technique for producing a good-quality single crystal thin film. With respect to yttrium (Y) -based and bismuth (Bi) -based oxide superconductors, fairly high-quality films have come to be obtained by methods such as sputtering and laser ablation. No film has been obtained.
【０００５】これは、前述のような真空中での気相成長
においては、Ｔｌのもつ高い蒸気圧のため、Ｔｌを膜中
に取り込ませることが難しく、成膜中に単結晶化してい
くいわゆるエピタキシャル成長が不可能であるためであ
る。一方、気相成長によらずに単結晶薄膜を得る方法と
して古くから知られているＬＰＥ（Liquid Phase Epita
xy）法を用いて酸化物超伝導体薄膜を得ようとする試み
も多く行われており、幾つかの超伝導物質についてはあ
る程度の成功を納めている。しかし、この方法も、フラ
ックスとして用いられているＣｕＯなどの融点が１００
０℃近くであり、Ｔｌの蒸発が問題となるＴｌ系超伝導
体に応用することは困難である。また、結晶育成後にお
ける試料のフラックス（ＣｕＯ）からの取り出しも極め
て困難である。This is because in vapor phase growth in a vacuum as described above, it is difficult to incorporate Tl into the film because of the high vapor pressure of Tl, and so-called single crystallization occurs during film formation. This is because epitaxial growth is impossible. On the other hand, LPE (Liquid Phase Epita), which has long been known as a method for obtaining a single crystal thin film without relying on vapor phase growth
Many attempts have been made to obtain oxide superconductor thin films using the (xy) method, and some success has been achieved for some superconducting materials. However, this method also has a melting point of 100 such as CuO used as a flux.
The temperature is near 0 ° C., and it is difficult to apply it to a Tl-based superconductor in which Tl evaporation is a problem. In addition, it is extremely difficult to take out the sample from the flux (CuO) after the crystal growth.
【０００６】これまでに得られたＴｌ系超伝導体薄膜の
ほとんどは、Ｔｌを除く元素からなる前駆体薄膜を通常
の薄膜成長法で作成し、その後Ｔｌ蒸気中で熱処理をす
るという方法で作られてきた。Most of the Tl-based superconductor thin films obtained thus far are produced by a method in which a precursor thin film made of an element other than Tl is prepared by an ordinary thin film growth method, and then heat treatment is performed in Tl vapor. Has been.
【０００７】[0007]
【発明が解決しようとする課題】上述した従来のＴｌ系
超伝導体薄膜の形成方法では、超伝導特性を疎外する粒
界を多く含んだ多結晶体しか得られないという欠点があ
るばかりでなく、組成むらや不純物相の析出が多く発生
するため、非常に超伝導特性の悪い膜しか得ることがで
きなかった。本願発明はこの点に鑑みてなされたもので
あって、その目的は、良質で大面積のＴｌ系超伝導体の
単結晶薄膜を再現性よく得る方法を提供することであ
る。The conventional method of forming a Tl-based superconductor thin film described above not only has the drawback that only a polycrystalline body containing a large number of grain boundaries that deviate from superconducting properties can be obtained. However, since the composition unevenness and the precipitation of the impurity phase are often generated, only the film having extremely poor superconducting properties could be obtained. The present invention has been made in view of this point, and an object thereof is to provide a method for obtaining a single crystal thin film of a high-quality, large-area Tl-based superconductor with good reproducibility.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するた
め、本発明によれば、（１）育成容器内に、基板を配置
するとともに、タリウム系酸化物焼結体粉末および融点
が９５０℃以下で水に可溶なフラックスを投入する段階
と、（２）前記育成容器を密閉するか、あるいは、前記
育成容器を密閉容器内に配置する段階と、（３）前記育
成容器ごと前記フラックスの融点以上の温度に加熱して
前記フラックスを融解させる段階と、（４）徐冷するこ
とにより、前記基板上にタリウム系酸化物を結晶成長さ
せる段階と、を含むタリウム系超伝導体薄膜の製造方
法、が提供される。In order to achieve the above object, according to the present invention, (1) a substrate is placed in a growth container, and a powder of thallium-based oxide and a melting point of 950 ° C. or less are used. The step of introducing a flux soluble in water in (2), or the step of sealing the growing container or placing the growing container in a closed container, and (3) the melting point of the flux with the growing container. A method for producing a thallium-based superconductor thin film, comprising the steps of heating to the above temperature to melt the flux, and (4) gradually cooling to cause crystal growth of a thallium-based oxide on the substrate. , Are provided.
【０００９】[0009]
【作用】本発明の薄膜の形成方法においては、Ｔｌ系酸
化物焼結体粉末を、低融点（９５０℃以下）のフラック
スとともに密閉容器内に収容し、ＬＰＥ法により基板上
に超伝導体薄膜を成長させる。この方法によれば、Ｔｌ
の蒸発を抑えることができるため、良質の単結晶薄膜を
安定して形成することが可能になる。In the thin film forming method of the present invention, the Tl-based oxide sintered body powder is housed in a closed container together with a flux having a low melting point (950 ° C. or lower), and the superconductor thin film is formed on the substrate by the LPE method. Grow. According to this method, Tl
Since it is possible to suppress the evaporation of the above, it becomes possible to stably form a high quality single crystal thin film.
【００１０】[0010]
【実施例】次に、本発明の実施例について図面を参照し
て説明する。 ［第１の実施例］Ｔｌ2 Ｏ3 、ＢａＯ、ＣａＯ、ＣｕＯ
を、金属比でＴｌ：Ｂａ：Ｃａ：Ｃｕ＝２：２：２：３
になるように混合し、所定の形状にプレスした後、金箔
に包んで５時間焼成し、Ｔｌ2 Ｂａ2 Ｃａ2 Ｃｕ3 Ｏ10
（Ｔｌ−２２２３）の単一相の多結晶試料を得た。この
焼結体を粉砕して粉末を得、これとＫＣｌを［Ｔｌ−２
２２３］／［ＫＣｌ］＝１ｗｔ．％の比率で混ぜ合わせ
た。Embodiments of the present invention will now be described with reference to the drawings. [First Embodiment] Tl 2 O 3 , BaO, CaO, CuO
At a metal ratio of Tl: Ba: Ca: Cu = 2: 2: 2: 3
The mixture is mixed into a mixture and pressed into a predetermined shape, wrapped in gold foil and baked for 5 hours, and then Tl 2 Ba 2 Ca 2 Cu 3 O 10
A single phase polycrystalline sample of (Tl-2223) was obtained. This sintered body was crushed to obtain a powder, which was mixed with KCl [T1-2
223] / [KCl] = 1 wt. % Mixed together.
【００１１】図１に示すように、金坩堝１内に基板ホル
ダー２を設置し、ここにＭｇＯ製の基板３をセットし
た。さらに、この金坩堝１内に、上記の焼結体粉末とＫ
Ｃｌとの混合物を充填した。次に、この坩堝を一回り大
きなアルミナ製坩堝にいれ蓋をした後、アルミナセメン
トで固めて密閉した。これを電気炉中にセットして、図
２に示すように、９４０℃まで昇温し、その温度で１０
時間保持した。その後、４０時間かけて７６５℃にまで
徐冷し、薄膜試料を作成した。室温まで炉冷した後、Ｋ
Ｃｌを水で流すことにより試料の取り出しを行った。得
られた試料についてＡｒ中で還元処理を施した。As shown in FIG. 1, a substrate holder 2 was set in a metal crucible 1 and a MgO substrate 3 was set therein. Further, in the metal crucible 1, the above-mentioned sintered powder and K
A mixture with Cl was charged. Next, this crucible was put into a crucible made of alumina, which was slightly larger than the crucible, and the lid was closed. This was set in an electric furnace, and the temperature was raised to 940 ° C. as shown in FIG.
Held for hours. Then, it was gradually cooled to 765 ° C. over 40 hours to prepare a thin film sample. After furnace cooling to room temperature, K
A sample was taken by flushing Cl with water. The obtained sample was subjected to reduction treatment in Ar.
【００１２】得られた薄膜の膜圧、結晶性をＳＥＭ（Sc
anning Electron Microscope）およびｘ線回折により評
価した結果、基板全面に２０００Åの厚みを持ち粒界の
無いＴｌ−２２２３単結晶膜が成長していることが明ら
かになった。電気抵抗率測定の結果、この試料は１１５
Ｋの超伝導開始温度（電気抵抗が下がり始める温度）と
１１３Ｋのゼロ抵抗温度（電気抵抗が完全に消失する温
度）を持つ薄膜であることが明らかになった。The film pressure and crystallinity of the obtained thin film were measured by SEM (Sc
As a result of evaluation by an anning electron microscope) and x-ray diffraction, it was revealed that a Tl-2223 single crystal film having a thickness of 2000Å and no grain boundary was grown on the entire surface of the substrate. As a result of electric resistivity measurement, this sample was 115
It was revealed that the thin film has a superconducting start temperature of K (temperature at which electric resistance begins to decrease) and a zero resistance temperature of 113K (temperature at which electric resistance completely disappears).
【００１３】［比較例１］第１の実施例と同じ材料を用
い、同一の結晶成長条件で容器を密閉せずに成長を行っ
た。この場合、全てのＴｌが育成中に蒸発してしまいＴ
ｌ系材料の薄膜は成長しなかった。[Comparative Example 1] The same material as in the first embodiment was used, and growth was performed under the same crystal growth conditions without sealing the container. In this case, all Tl evaporates during the growth,
No thin film of l-based material grew.
【００１４】［比較例２］また、第１の実施例に対しＫ
Ｃｌの代わりにＣｕＯフラックスを用いた場合は、Ｃｕ
Ｏフラックスの融点がＫＣｌよりも高いため高温に保持
する必要があり、この場合は坩堝を密閉してもほとんど
のＴｌが蒸発してしまいＴｌ系材料の結晶は成長しなか
った。[Comparative Example 2] Also, in comparison with the first embodiment, K
If CuO flux is used instead of Cl,
Since the melting point of O-flux is higher than that of KCl, it must be maintained at a high temperature. In this case, even if the crucible was sealed, most of Tl was evaporated and crystals of Tl-based material did not grow.
【００１５】［第２の実施例］第１の実施例の場合と同
様の方法により、Ｔｌ2 Ｏ3 、ＢａＯ、ＣａＯ、ＣｕＯ
からＴｌ2 Ｂａ2 ＣｕＯ6 （Ｔｌ−２２１２）の焼結体
を合成した。この焼結体を粉砕して粉末を得、これと、
ＫＣｌとＮａＣｌとを１：１の比率で混合した混合物と
を［Ｔｌ−２２１２］／［ＫＣｌ＋ＮａＣｌ］＝２ｗ
ｔ．％となるように混合し、予めＳｒＴｉＯ3 基板がセ
ットされた金坩堝内に充填した。[Second Embodiment] Tl 2 O 3 , BaO, CaO, CuO is prepared in the same manner as in the first embodiment.
A sintered body of Tl 2 Ba 2 CuO 6 (Tl-2212) was synthesized from. This sintered body is crushed to obtain powder, and
A mixture of KCl and NaCl mixed at a ratio of 1: 1 was added to [T1-2212] / [KCl + NaCl] = 2w.
t. %, And the mixture was filled in a metal crucible in which a SrTiO 3 substrate was set in advance.
【００１６】この金坩堝に金の蓋を溶接し密閉した後、
これを電気炉中にセットした。そして、図２に示すよう
に、９３５℃まで昇温し、その温度で５時間保持した。
その後、２４時間かけて７００℃にまで徐冷して薄膜試
料を作成した。放置して室温まで冷却させた後、ＫＣｌ
とＮａＣｌを水で流して、坩堝より試料を取り出した。After a gold lid is welded to the gold crucible and sealed,
This was set in an electric furnace. Then, as shown in FIG. 2, the temperature was raised to 935 ° C. and the temperature was maintained for 5 hours.
Then, it was gradually cooled to 700 ° C. over 24 hours to prepare a thin film sample. After leaving it to cool to room temperature, KCl
And NaCl were flushed with water, and the sample was taken out from the crucible.
【００１７】得られた膜は、ＳＥＭによる解析およびｘ
線回折による評価により、基板全面に均一な膜厚に形成
されたＴｌ−２２１２単結晶薄膜であることがわかっ
た。また、電気抵抗率測定の結果、得られた薄膜は１０
５Ｋの超伝導開始温度と１０３Ｋのゼロ抵抗温度を示す
良好な超伝導体であった。The obtained film was analyzed by SEM and x
The evaluation by line diffraction revealed that it was a Tl-2212 single crystal thin film formed in a uniform film thickness on the entire surface of the substrate. In addition, as a result of measurement of electric resistivity, the obtained thin film was 10
It was a good superconductor showing a superconducting start temperature of 5K and a zero resistance temperature of 103K.
【００１８】［第３の実施例］第１の実施例の場合と同
様の方法により、Ｔｌ2 Ｏ3 、ＢａＯ、ＣｕＯからＴｌ
2 Ｂａ2 ＣｕＯ6 （Ｔｌ−２２０１）の焼結体を合成し
た。この焼結体を粉砕して粉末を得、これとＫＣｌとを
［Ｔｌ−２２０１］／［ＫＣｌ］＝５ｗｔ．％となるよ
うに混合した。この混合物を、予めＭｇＯ基板がセット
された金坩堝内に充填した。[Third Embodiment] Tl 2 O 3 , BaO, CuO to Tl are processed in the same manner as in the first embodiment.
A sintered body of 2 Ba 2 CuO 6 (T1-220) was synthesized. This sintered body was crushed to obtain a powder, and this powder and KCl were mixed with [T1-220] / [KCl] = 5 wt. It mixed so that it might become%. This mixture was filled in a metal crucible in which a MgO substrate was set in advance.
【００１９】この金坩堝に金の蓋を溶接し、密閉した
後、これを電気炉中にセットした。そして、図２に示す
ように、９２０℃まで昇温し、その温度で３時間保持し
た。その後、４０時間かけて７６５℃にまで徐冷して薄
膜試料を作成した。放置して室温まで冷却した後試料を
取り出した。試料の取り出しはＫＣｌを水で流すことに
より行った。得られた試料についてＡｒ中で還元処理を
施した。A gold lid was welded to the gold crucible and sealed, and then set in an electric furnace. Then, as shown in FIG. 2, the temperature was raised to 920 ° C. and the temperature was maintained for 3 hours. Then, it was gradually cooled to 765 ° C. over 40 hours to prepare a thin film sample. After leaving it to cool to room temperature, the sample was taken out. The sample was taken out by flushing KCl with water. The obtained sample was subjected to reduction treatment in Ar.
【００２０】得られた膜は、ＳＥＭによる解析およびｘ
線回折による評価により、基板全面に均一に１０００Å
の膜厚に形成されたＴｌ−２２０１単結晶薄膜であるこ
とがわかった。また、電気抵抗率測定の結果、得られた
薄膜は９２Ｋの超伝導開始温度と９０Ｋのゼロ抵抗温度
を示す良好な超伝導体であった。The obtained film was analyzed by SEM and x
Equally 1000Å on the entire surface of the substrate as evaluated by line diffraction
It was found to be a T1-220 single crystal thin film having a film thickness of. As a result of electric resistivity measurement, the obtained thin film was a good superconductor showing a superconducting start temperature of 92K and a zero resistance temperature of 90K.
【００２１】なお、特に実施例として説明はしないが、
図２に示すように、およびに示す材料について、そ
れぞれ図２に示す処理を行うことにより、第１〜第３の
実施例の場合と同様の良好な品質のＴｌ−２２０１単結
晶および薄膜Ｔｌ−２２２３単結晶薄膜を得ることがで
きた。Although not specifically described as an embodiment,
By performing the treatments shown in FIGS. 2A and 2B on the materials shown in FIGS. 2A and 2B, respectively, a T1-220 single crystal and a thin film Tl- of the good quality similar to those in the first to third embodiments are obtained. A 2223 single crystal thin film could be obtained.
【００２２】[0022]
【発明の効果】以上説明したように、本発明による超伝
導体薄膜の製造方法は、ＫＣｌなどの低融点フラックス
とＴｌ系酸化物との混合物を密閉容器内に収容して結晶
成長を行なうものであるので、結晶育成中でのＴｌの蒸
発を防止することができ、従来困難であった良質なＴｌ
系超伝導体単結晶薄膜のエピタキシャル成長が可能にな
る。したがって、本発明により、Ｔｌ系超伝導体の電子
デバイスへの応用が可能となる。As described above, in the method for producing a superconductor thin film according to the present invention, a mixture of a low melting point flux such as KCl and a Tl-based oxide is contained in a closed container for crystal growth. Therefore, it is possible to prevent evaporation of Tl during crystal growth, and it is possible to prevent high quality Tl which was difficult in the past.
Enables epitaxial growth of single crystal thin films of superconductors. Therefore, the present invention makes it possible to apply the Tl-based superconductor to electronic devices.
【図１】本発明の実施例において用いられる金坩堝に基
板をセットした状態を示す断面図。FIG. 1 is a cross-sectional view showing a state where a substrate is set in a metal crucible used in an embodiment of the present invention.
【図２】本発明の実施例の熱処理条件を説明するための
グラフ。FIG. 2 is a graph for explaining heat treatment conditions according to an example of the present invention.
１ 金坩堝 ２ 基板ホルダー ３ 基板 1 gold crucible 2 substrate holder 3 substrate
フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０１Ｂ 13/00 ５６５ Ｄ Ｈ０１Ｌ 39/24 ＺＡＡ Ｂ // Ｈ０１Ｌ 39/02 Ｂ Continuation of the front page (51) Int.Cl. 6 Identification code Office reference number FI Technical display location H01B 13/00 565 D H01L 39/24 ZAA B // H01L 39/02 B
Claims (5)
ともに、タリウム系酸化物焼結体および融点が９５０℃
以下で水に可溶なフラックスを投入する段階と、 （２）前記育成容器を密閉するか、あるいは、前記育成
容器を密閉容器内に配置する段階と、 （３）前記育成容器ごと前記フラックスの融点以上の温
度に加熱して前記フラックスを融解させる段階と、 （４）徐冷することにより、前記基板上にタリウム系酸
化物を結晶成長させる段階と、を含むことを特徴とする
タリウム系超伝導体薄膜の製造方法。1. A substrate is placed in a growth container, and a thallium-based oxide sintered body and a melting point are 950 ° C.
In the following, a step of introducing a flux soluble in water, (2) a step of sealing the growing container or a step of placing the growing container in a closed container, (3) a step of adding the flux to the growing container together with the flux A thallium-based super alloy, comprising: a step of melting the flux by heating to a temperature equal to or higher than a melting point; and (4) a step of gradually cooling to cause crystal growth of a thallium-based oxide on the substrate. Manufacturing method of conductor thin film.
ム系酸化物焼結体は粉末状のものであって、これとフラ
ックスとを混合した後に前記育成容器内に投入すること
を特徴とする請求項１記載のタリウム系超伝導体薄膜の
製造方法。2. In the step (1), the thallium-based oxide sintered body is in the form of powder, and the thallium-based oxide sintered body is mixed with a flux and then charged into the growth container. The method for producing a thallium-based superconductor thin film according to claim 1.
はそれらの混合物であることを特徴とする請求項１記載
のタリウム系超伝導体薄膜の製造方法。3. The method for producing a thallium-based superconductor thin film according to claim 1, wherein the flux is KCl, NaCl or a mixture thereof.
の融解した状態で一定時間所定の温度に保持することを
特徴とする請求項１記載のタリウム系超伝導体薄膜の製
造方法。4. The method for producing a thallium-based superconductor thin film according to claim 1, wherein, in the step (3), the flux is melted and kept at a predetermined temperature for a certain period of time.
り基板を取り出し、不活性ガス中において、還元処理を
施すことを特徴とする請求項１記載のタリウム系超伝導
体薄膜の製造方法。5. The production of a thallium-based superconductor thin film according to claim 1, wherein after the step (4), the substrate is taken out of the growth container and subjected to reduction treatment in an inert gas. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7023342A JPH08198700A (en) | 1995-01-19 | 1995-01-19 | Production of thin film of thallium-containing superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7023342A JPH08198700A (en) | 1995-01-19 | 1995-01-19 | Production of thin film of thallium-containing superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08198700A true JPH08198700A (en) | 1996-08-06 |
Family
ID=12107926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7023342A Pending JPH08198700A (en) | 1995-01-19 | 1995-01-19 | Production of thin film of thallium-containing superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08198700A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107437579A (en) * | 2017-09-18 | 2017-12-05 | 广西师范学院 | The Fast Sintering preparation method of the superconducting thin films of Tl 2212 |
| CN107482110A (en) * | 2017-09-18 | 2017-12-15 | 广西师范学院 | The preparation method of Tl‑2223 superconducting film |
| CN107602112A (en) * | 2017-09-18 | 2018-01-19 | 广西师范学院 | The preparation method of the superconducting thin films of Tl 1223 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0393607A (en) * | 1989-09-04 | 1991-04-18 | Ibiden Co Ltd | Production of superconductor |
-
1995
- 1995-01-19 JP JP7023342A patent/JPH08198700A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0393607A (en) * | 1989-09-04 | 1991-04-18 | Ibiden Co Ltd | Production of superconductor |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107437579A (en) * | 2017-09-18 | 2017-12-05 | 广西师范学院 | The Fast Sintering preparation method of the superconducting thin films of Tl 2212 |
| CN107482110A (en) * | 2017-09-18 | 2017-12-15 | 广西师范学院 | The preparation method of Tl‑2223 superconducting film |
| CN107602112A (en) * | 2017-09-18 | 2018-01-19 | 广西师范学院 | The preparation method of the superconducting thin films of Tl 1223 |
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