JPH01215717A - Superconducting material and production thereof - Google Patents
Superconducting material and production thereofInfo
- Publication number
- JPH01215717A JPH01215717A JP63042698A JP4269888A JPH01215717A JP H01215717 A JPH01215717 A JP H01215717A JP 63042698 A JP63042698 A JP 63042698A JP 4269888 A JP4269888 A JP 4269888A JP H01215717 A JPH01215717 A JP H01215717A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- superconducting
- raw material
- superconducting material
- sintering
- 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.)
- Granted
Links
- 239000000463 material Substances 0.000 title claims abstract description 46
- 238000004519 manufacturing process Methods 0.000 title claims description 18
- 239000000843 powder Substances 0.000 claims abstract description 54
- 239000000203 mixture Substances 0.000 claims abstract description 25
- 238000005245 sintering Methods 0.000 claims abstract description 24
- 239000002994 raw material Substances 0.000 claims abstract description 22
- 150000001875 compounds Chemical class 0.000 claims abstract description 8
- 230000000737 periodic effect Effects 0.000 claims abstract description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 4
- 238000001354 calcination Methods 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 21
- 239000002131 composite material Substances 0.000 claims description 15
- 238000010304 firing Methods 0.000 claims description 12
- 239000010409 thin film Substances 0.000 claims description 11
- 238000005240 physical vapour deposition Methods 0.000 claims description 6
- 239000000758 substrate Substances 0.000 claims description 6
- 238000010298 pulverizing process Methods 0.000 claims description 4
- 229910002651 NO3 Inorganic materials 0.000 claims description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 3
- 238000007733 ion plating Methods 0.000 claims description 3
- 238000004544 sputter deposition Methods 0.000 claims description 3
- 238000007493 shaping process Methods 0.000 claims description 2
- 239000002245 particle Substances 0.000 abstract description 9
- 239000002887 superconductor Substances 0.000 abstract description 4
- 238000000227 grinding Methods 0.000 abstract description 3
- 238000002156 mixing Methods 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract 2
- 239000002243 precursor Substances 0.000 abstract 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 239000013078 crystal Substances 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010894 electron beam technology 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
- 239000012535 impurity Substances 0.000 description 2
- 238000009616 inductively coupled plasma Methods 0.000 description 2
- 230000005291 magnetic effect Effects 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000005292 diamagnetic effect Effects 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005339 levitation Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000003891 oxalate salts Chemical class 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000002560 therapeutic procedure Methods 0.000 description 1
- 238000007740 vapor deposition Methods 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)
- Physical Vapour Deposition (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、超電導材料およびその製造方法に関する。よ
り詳細には、本発明は、極めて高い温度で超電導現象を
示す新規な超電導材料並びにその製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to superconducting materials and methods for producing the same. More particularly, the present invention relates to a novel superconducting material that exhibits superconducting phenomena at extremely high temperatures, and a method for producing the same.
従来の技術
特定の物質は、超電導現象下で反磁性を示し、内部に有
限な定常電流が流れているにも関わらず電位差が現れな
くなる。BACKGROUND OF THE INVENTION Certain materials exhibit diamagnetic properties under superconducting phenomena, and no potential difference appears even though a finite steady current flows inside them.
この超電導現象の応用分野は、ＭＨＤ発電、電力送電、
電力貯蔵等の電力分野、或いは、磁気浮上列車、電磁気
推進船舶等の動力分野、更に、磁場、高周波、放射線等
の超高感度センサとしてＮＭＲ１π中間子治療、高エネ
ルギー物理実験装置などの計測の分野等、極めて広範な
分野に渡っており、更に、ジョセフソン素子に代表され
るエレクトロニクスの分野でも、単に消費電力の低減の
みならず、動作の極めて高速な素子を実現し得る技術と
して期待されている。The fields of application of this superconducting phenomenon are MHD power generation, power transmission,
In the power field such as power storage, in the power field such as magnetic levitation trains and electromagnetic propulsion ships, and in the field of measurement such as NMR1π meson therapy and high energy physical experiment equipment as ultra-sensitive sensors for magnetic fields, high frequencies, radiation, etc. This technique is used in an extremely wide range of fields, and is also expected to be used in the field of electronics, such as Josephson devices, as a technology that not only reduces power consumption but also realizes devices that operate at extremely high speeds.
ところで、嘗て超電導は超低温下においてのみ観測され
る現象であった。即ち、従来の超電導材料として最も高
い超電導臨界温度Ｔｃを有するといわれていたＮｂ、Ｇ
ｅにおいても２３．２ Ｋという極めて低い温度が長期
間に亘って超電導臨界温度の限界とされていた。By the way, superconductivity was once a phenomenon observed only at extremely low temperatures. That is, Nb and G, which are said to have the highest superconducting critical temperature Tc among conventional superconducting materials,
For a long time, an extremely low temperature of 23.2 K was considered to be the limit of superconducting critical temperature.
それ故、従来は、超電導現象を実現するために、沸点が
４．２にの液体ヘリウムを用いて超電導材料をＴｃ以下
まで冷却していた。しかしながら、液体ヘリウムの使用
は、液化設備を含めた冷却設備による技術的負担並びに
コスト的負担が極めて大きく、超電導技術の実用化への
妨げとなっていた。Therefore, conventionally, in order to realize the superconducting phenomenon, superconducting materials have been cooled to below Tc using liquid helium with a boiling point of 4.2. However, the use of liquid helium imposes an extremely large technical burden and cost burden due to cooling equipment including liquefaction equipment, which has hindered the practical application of superconducting technology.
ところが、近年に到って複合酸化物焼結体が高い臨界温
度で超電導体となり得ることが報告され、非低温超電導
体による超電導技術の実用化が俄かに促進されようとし
ている。既に報告されている例では、Ｙ −Ｂａ−Ｃｕ
系等の３元素系複合酸化物でペロブスカイト型に類似し
た結晶構造を有するものが、液体窒素温度以上で超電導
現象を示すものとして報告されている。However, in recent years, it has been reported that composite oxide sintered bodies can become superconductors at high critical temperatures, and the practical application of superconducting technology using non-low temperature superconductors is rapidly gaining momentum. In already reported examples, Y-Ba-Cu
It has been reported that three-element complex oxides such as 3-element composite oxides having crystal structures similar to perovskite-type exhibit superconductivity at temperatures above liquid nitrogen temperature.
発明が解決しようとする課題
液体窒素は、入手が比較的容易で廉価なので、液体窒素
温度で動作する超電導材料の発見を以って超電導技術の
実用化が大きく進歩したことは事実である。しかしなが
ら、これとても基本的な冷却設備の構成は変わらず、専
ら冷却媒体の低価格化による超電導技術の低コスト化を
実現し得たに過ぎない。Problems to be Solved by the Invention Since liquid nitrogen is relatively easy to obtain and inexpensive, it is true that the discovery of superconducting materials that operate at liquid nitrogen temperatures has greatly advanced the practical application of superconducting technology. However, the very basic configuration of the cooling equipment has not changed, and the cost reduction of superconducting technology has only been realized by lowering the cost of the cooling medium.
また、超電導状態の安定性を考慮すると、冷却媒体の温
度（特に沸点）とその材料の超電導臨界温度Ｔｃとの間
に十分な差があることが望ましく、実用的には超電導材
料の臨界温度をより向上する必要がある。In addition, considering the stability of the superconducting state, it is desirable that there is a sufficient difference between the temperature of the cooling medium (especially the boiling point) and the superconducting critical temperature Tc of the material. We need to improve further.
そこで、本発明は、冷却設備による超電導技術利用の制
限を軽減し、安定に超電導現象を利用することのできる
、更に高温で超電導特性を示す新規な超電導材料とその
製造方法を提供することを目的としている。Therefore, an object of the present invention is to provide a new superconducting material that exhibits superconducting properties at high temperatures and a method for manufacturing the same, which can alleviate the restrictions on the use of superconducting technology due to cooling equipment and stably utilize the superconducting phenomenon. It is said that
課題を解決するための手段
即ち、本発明に従い、
式： ＴＩＸβ、 Ｂａ Ｃｕ、 Ｏａ〔但し、元素β
は周期律表［ａ族から選択されたＢａ以外の元素であり
、ｘＳｙ、ｚは、それぞれ０．５≦ｘ≦３．０
０．５≦ｙ≦３．０
０．９≦２≦４．０を満たす数である〕で示される組成
を有する複合酸化物を主として含むことを特徴とする超
電導材料が提供される。Means for solving the problem, ie, according to the present invention, Formula: TIXβ, Ba Cu, Oa [However, element β
is an element other than Ba selected from group a of the periodic table, and xSy and z are respectively 0.5≦x≦3.0 0.5≦y≦3.0 0.9≦2≦4. A superconducting material is provided, which is characterized in that it mainly contains a composite oxide having a composition represented by the following formula: (a number satisfying 0).
尚、上記式において、ＸＳＹ％Ｚのより好ましい範囲と
して、
１．５≦ｘ≦２．５
１．５≦ｙ≦２．５
２．５≦Ｚ≦３．５
を挙げることができる。In the above formula, more preferable ranges of XSY%Z include the following: 1.5≦x≦2.5 1.5≦y≦2.5 2.5≦Z≦3.5.
また、上記超電導材料を製造する方法として、本発明に
より、第１請求項に記載の超電導材料を製造する方法で
あって、前記Ｔｌ、 Ｂａ、並びにＣｕの各単体、該元
素のうちの少なくともひとつを含む化合物から選択した
原料粉末を該元素を全て含むように混合した混合物、あ
るいは、該混合物を焼成焼成後に粉砕して得た焼成体粉
末を焼結する工程を少なくとも１回含むことを特徴とす
る超電導材料の製造方法が提供される。Further, as a method for manufacturing the superconducting material, there is provided a method for manufacturing the superconducting material according to the first claim according to the present invention, which comprises at least one of each element of Tl, Ba, and Cu, and at least one of the elements. It is characterized by including at least one step of sintering a mixture of raw material powders selected from compounds containing the elements so as to contain all of the elements, or a fired body powder obtained by pulverizing the mixture after firing. A method for manufacturing a superconducting material is provided.
ここで、原料粉末としては、各元素の単体の他に、前記
元素群から選択された少なくとも１種以上の元素の酸化
物、炭酸塩、硫酸塩、硝酸塩または蓚酸塩の粉末を使用
することができるが、特に製品の品質を考慮すると酸化
物が、また、原料粉末の調製の容易さを考慮すると炭酸
塩等が有利である。また、炭酸塩、硫酸塩、硝酸塩また
は蓚酸塩の粉末を原料粉末に使用した場合は、焼結に先
立って仮焼を実施し、これらに含まれる炭素、硫黄、窒
素等を除去することも、製品の品質を向上するために有
利である。Here, as the raw material powder, in addition to each element alone, powders of oxides, carbonates, sulfates, nitrates, or oxalates of at least one element selected from the above element groups may be used. However, from the viewpoint of product quality, oxides are preferred, and from the viewpoint of ease of preparation of raw material powder, carbonates are preferred. Additionally, if carbonate, sulfate, nitrate, or oxalate powder is used as the raw material powder, calcination may be performed prior to sintering to remove carbon, sulfur, nitrogen, etc. contained in these powders. It is advantageous to improve product quality.
本発明に従う超電導材料の製造方法において、本発明の
好ましい態様に従うと、前記焼成体の粉砕並びに該焼成
体粉末を整形して焼結する工程は、２回以上に亘って反
復することができる。また、焼成または焼結に付される
成形体を形成する複合酸化物を含む粉末の粒径は１０μ
ｍ以下とすることが有利であり、より好ましくはｌ乃至
５μｍの範囲とすることが好ましい。In the method for producing a superconducting material according to the present invention, according to a preferred embodiment of the present invention, the steps of pulverizing the sintered body, shaping and sintering the sintered body powder can be repeated two or more times. In addition, the particle size of the powder containing the composite oxide that forms the compact that is subjected to firing or sintering is 10 μm.
It is advantageous that the thickness is less than m, more preferably in the range of 1 to 5 μm.
焼成並びに焼結工程における焼結温度は、７５０℃以上
の温度であって、使用する原料粉末のうち最も融点の低
い化合物の融点を上限とする温度範囲で行うことが好ま
しく、より具体的には、８００乃至９００℃の温度範囲
を挙げることができる。また、焼結時間は１時間乃至５
０時間保持することが好ましいが、これに限定されない
。The sintering temperature in the firing and sintering process is preferably 750°C or higher, and is preferably carried out in a temperature range whose upper limit is the melting point of the compound with the lowest melting point among the raw material powders used. , 800 to 900°C. Also, the sintering time is 1 hour to 5 hours.
It is preferable to hold for 0 hours, but it is not limited thereto.
さて、本発明に従って提供される超電導材料は、上述の
ようにして得た原料粉末、焼成体または焼結体をターゲ
ットとして、物理蒸着によって所定の基板上に薄膜とし
て成長させることもできる。Now, the superconducting material provided according to the present invention can also be grown as a thin film on a predetermined substrate by physical vapor deposition using the raw material powder, fired body, or sintered body obtained as described above as a target.
但し、ターゲットの組成は、形成される薄膜の組成が前
記超電導材料の組成となるように、ターゲットを構成す
る各元素の蒸発速度等に応じて調整することが好ましい
。尚、この本発明による方法において、本発明の一実施
態様に従うと、前記物理蒸着としては、スパッタリング
法、電子ビーム法、イオンプレーティング法の何れかを
選択することができる。また、薄膜を成長させる基板と
しては、ＭｇＯ１ＢａＴｔ０３．５１０２ 、す７フイ
ヤ、ＹＳＺ等を好ましいものとして例示することができ
る。However, the composition of the target is preferably adjusted according to the evaporation rate of each element constituting the target, etc. so that the composition of the thin film to be formed is the composition of the superconducting material. In addition, in the method according to the present invention, according to one embodiment of the present invention, any one of sputtering method, electron beam method, and ion plating method can be selected as the physical vapor deposition method. Further, as a substrate on which a thin film is grown, MgO1BaTt03.5102, Su7fire, YSZ, etc. can be exemplified as preferable substrates.
作用
本発明の方法により得られる超電導材料は、前記従来技
術の問題点に鑑みて、本発明者等が種々の組成の複合酸
化物焼結体について、試料の作製と測定を重ねた結果見
出されたものである。即ち、本発明に係る超電導材料は
、
式ゴ１．ｌβｙ Ｂａ ［：ｕ、 ｏａ〔但し、元素β
は周期律表［ａ族から選択されたＢａ以外の元素であり
、Ｘ５Ｖｓ ｚは、それぞれ０．５≦ｘ≦３．０
０．５≦ｙ≦３．０
０．９≦２≦４．０を満たす数である〕で示される組成
を主として含むことをその主要な特徴としている。Function: The superconducting material obtained by the method of the present invention was discovered as a result of the repeated preparation and measurement of samples of composite oxide sintered bodies of various compositions by the present inventors, in view of the problems of the prior art described above. It is what was done. That is, the superconducting material according to the present invention has the following formula: 1. lβy Ba [:u, oa [However, element β
is an element other than Ba selected from group a of the periodic table, and X5Vs z is 0.5≦x≦3.0 0.5≦y≦3.0 0.9≦2≦4.0 Its main feature is that it mainly contains the composition shown in
尚、本発明に従う超電導材料は、上述のような式で示さ
れる複合酸化物を主として含むが、必ずしも厳密にこの
比に限定されるものではなく、これらの比から±５０％
の範囲、さらに好ましくは±２０％の範囲内の組成を有
するものでも有効な超電導特性を示す場合がある。即ち
、特許請求の範囲において「上記の式で表される複合酸
化物を主として含む」という表現は、本発明の方法によ
って作製された超電導薄膜が、上記式で定義される原子
比以外のものも含むということを意味している。Although the superconducting material according to the present invention mainly contains a composite oxide represented by the above formula, it is not necessarily strictly limited to this ratio, and ±50% from these ratios.
Even those having a composition within a range of 20%, more preferably within a range of ±20%, may exhibit effective superconducting properties. That is, in the claims, the expression "mainly contains a complex oxide represented by the above formula" means that the superconducting thin film produced by the method of the present invention may have an atomic ratio other than that defined by the above formula. It means including.
この本発明に従う超電導材料は、具体的に後述するよう
に、極めて優れた超電導特性を示すと共に、安定性の点
でも優れており、待機中でも長期間に亘って有効な超電
導特性を発揮する。As will be specifically described below, the superconducting material according to the present invention exhibits extremely excellent superconducting properties and is also excellent in stability, exhibiting effective superconducting properties over a long period of time even during standby.
尚、本発明に従う超電導材料は、上記組成以外の元素、
即ち、ｐｐｍオーダーで混入する不可避的不純物あるい
は得られる焼結体または薄膜の他の特性を向上させる目
的で添加される第３成分を含有していてもよい。具体的
な第３成分としては、周期律表ＩＩａ族元素、１ｌｌａ
族元素を例示することができる。Note that the superconducting material according to the present invention contains elements other than the above composition,
That is, it may contain unavoidable impurities mixed in on the order of ppm or a third component added for the purpose of improving other properties of the obtained sintered body or thin film. Specific third components include Group IIa elements of the periodic table, 1lla
Examples include group elements.
上述のような複合酸化物を主として含む超電導材料は、
焼結体としであるいは薄膜として得ることができる。Superconducting materials mainly containing composite oxides as described above are
It can be obtained as a sintered body or as a thin film.
焼結体としての複合酸化物材料を製造する場合、本発明
者等の研究によれば、超電導材料として高い特性を発揮
する焼結体を製造するには以下のような点についての厳
重な管理が必要である。When manufacturing a composite oxide material as a sintered body, according to research by the present inventors, in order to manufacture a sintered body that exhibits high characteristics as a superconducting material, the following points must be strictly controlled. is necessary.
■原料粉末の粒径
■焼成温度
■焼成処理並びに粉砕後の焼成体粉末の粒径■焼結温度
即ち、焼成処理前の原料粉末の平均粒径が、１０μｍを
越えると、焼結後の粉砕工程を経た後も、結晶粒の十分
な微細化ができない。従って、結晶粒径の微細化を図る
ためには原料粉末の粒径が１０μｍ以下、好ましくは１
乃至５μｍの範囲であることが好ましい。尚、１乃至５
μｍとした理由は、５μｍ以下とすることによって粉末
の細粒化の降下が顕著に得られる一方、１μｍ以下に粉
砕することは、作業時間の点や不純物の混入等の点から
工業的に不利であるからである。また、特に最終焼結に
付す粉末の細粒化は、製品の結晶粒径に直接的な影響が
あるので、この点に特に留意すべきである。また、これ
ら一連の〔焼成→粉砕→成形〕工程を複数回繰り返すこ
とによって、原料粉末あるいは焼成体を均質化すること
ができ、品質の高い製品を得ることができる。■ Particle size of raw material powder ■ Firing temperature ■ Particle size of fired body powder after firing treatment and crushing ■ Sintering temperature, that is, if the average particle size of raw material powder before firing treatment exceeds 10 μm, crushing after sintering Even after the process, crystal grains cannot be sufficiently refined. Therefore, in order to reduce the crystal grain size, the particle size of the raw material powder should be 10 μm or less, preferably 1 μm or less.
The thickness is preferably in the range of 5 μm to 5 μm. In addition, 1 to 5
The reason for choosing µm is that while grinding to 5 µm or less will significantly reduce the fineness of the powder, grinding to 1 µm or less is industrially disadvantageous in terms of working time and contamination with impurities. This is because. In addition, particular attention should be paid to the refinement of the powder to be subjected to final sintering, as this has a direct effect on the crystal grain size of the product. Furthermore, by repeating these series of steps (firing → crushing → molding) multiple times, the raw material powder or the fired body can be homogenized and a high quality product can be obtained.
焼結温度は、超電導材料を製造する際の重要な制御因子
であり、焼結中に材料に溶融が生ずることなく固相反応
のみで焼結が進行すること、並びに、焼結して形成され
た複合酸化物の結晶成長が過大とならないように制御す
る必要がある。従って、焼結温度は焼成体粉末の融点を
越えない温度で行う必要がある。但し、焼結温度が低す
ぎると十分な焼結反応が得られないので、少なくとも７
５０℃以上に加熱する必要がある。また、焼結時間は、
−船釣に長い程好ましい組成が得られるが、実際的には
１時間乃至５０時間程度が好ましい。The sintering temperature is an important controlling factor when producing superconducting materials, and it is important that sintering proceeds only by solid-phase reaction without melting of the material during sintering, and that the material is formed by sintering. It is necessary to control the crystal growth of the composite oxide so that it does not become excessive. Therefore, the sintering must be carried out at a temperature that does not exceed the melting point of the sintered powder. However, if the sintering temperature is too low, sufficient sintering reaction cannot be obtained, so at least 7
It is necessary to heat it to 50°C or higher. In addition, the sintering time is
- The longer the fishing time on a boat, the better the composition, but in practice, about 1 to 50 hours is preferable.
更に、上述の焼結処理の制御と同様の理由で焼成処理の
管理も厳重に管理さるべきものである。Furthermore, for the same reason as the control of the sintering process described above, the management of the firing process should also be strictly controlled.
即ち、焼成温度が８００℃に達しない場合は焼成反応が
十分に進行せず、所望の組成物が得られない。That is, if the firing temperature does not reach 800°C, the firing reaction will not proceed sufficiently and the desired composition will not be obtained.
一方、加熱温度が原料粉末の融点を越えることが好′ま
しくないことは前述の通りである。On the other hand, as mentioned above, it is not preferable for the heating temperature to exceed the melting point of the raw material powder.
上述のような多元素系複合酸化物超電導材料は、物理蒸
着によって基板上に薄膜として成長させることもできる
。この場合、蒸発源としては、超電導材料を形成する各
元素そのもの、またはこれらの元素の各化合物の粉末の
混合物はもとより、これらを混合して焼成することによ
って得られる焼成体またはその粉末、あるいは、この焼
成体粉末または前記各化合物粉末を焼結して得られる焼
結体またはその粉末を用いることができる。物理蒸着は
、スパッタリング法、電子ビーム法、イオンプレーティ
ング法等を具体的な例として挙げることができる。The multi-element complex oxide superconducting material as described above can also be grown as a thin film on a substrate by physical vapor deposition. In this case, the evaporation source may include each element forming the superconducting material itself, a powder mixture of each compound of these elements, a fired body obtained by mixing and firing these elements, or its powder, This sintered body powder or a sintered body obtained by sintering each of the above compound powders or a powder thereof can be used. Specific examples of physical vapor deposition include sputtering, electron beam, and ion plating.
尚、成膜する複合酸化物の組成比が適切な組成比を有す
るように、各元素の蒸着効率に応じて蒸発源の各元素の
組成比および／または酸素分圧を調整しておくことが好
ましい。また、成膜に際して用いる基板は、形成する複
合酸化物と結晶構造の類似したものを用いることが有利
である。In addition, the composition ratio of each element of the evaporation source and/or the oxygen partial pressure may be adjusted according to the vapor deposition efficiency of each element so that the composition ratio of the composite oxide to be formed has an appropriate composition ratio. preferable. Furthermore, it is advantageous to use a substrate used for film formation that has a similar crystal structure to the composite oxide to be formed.
以下に本発明を実施例により具体的に説明するが、以下
の開示は本発明の一実施例に過ぎず、本発明の技術的範
囲を何等制限するものではない。EXAMPLES The present invention will be specifically explained below with reference to examples, but the disclosure below is only one example of the present invention and does not limit the technical scope of the present invention in any way.
実施例
まず、市販のＢａＣＯ３粉末、ＣａＣＯ５粉末並びにＣ
ｕＯ粉末を、ボールミルを使用して粒径ｌＯμｍ程度ま
で粉砕すると共に混合した。この粉末混合物を、９２５
℃で３０分焼成して、Ｂａ−Ｃａ −Ｃｕ−０の焼成体
を得た。Example First, commercially available BaCO3 powder, CaCO5 powder and C
The uO powder was ground to a particle size of about 10 μm using a ball mill and mixed. This powder mixture was mixed with 925
It was baked at ℃ for 30 minutes to obtain a baked body of Ba-Ca-Cu-0.
得られた焼成体を、再びボールミルで１０μｍ以下まで
粉砕した後に、７１２０３粉末と元素βの酸化物粉末を
それぞれ更に加え、粒径が５μｍ以下になるまで粉砕／
混合して原料粉末■、■、■を得た。尚、ここで使用し
た元素βとは、■／ ！、１ ｇ、■／Ｃａ、■／Ｓｒ
である。また、得られた原料粉末は、該原料粉末中の各
元素の原子比Ｔｌ：β： Ｂａ ： Ｃｕが２：２：１
：３となるように調製した。After pulverizing the obtained fired body to a particle size of 10 μm or less using a ball mill, 71203 powder and an oxide powder of element β were further added thereto, and pulverized/pulverized until the particle size became 5 μm or less.
By mixing, raw material powders ①, ②, and ② were obtained. The element β used here is ■/! , 1 g, ■/Ca, ■/Sr
It is. In addition, the obtained raw material powder has an atomic ratio of each element in the raw material powder Tl:β:Ba:Cu of 2:2:1.
:3.
こうして得られた原料粉末をプレス成形した後、９００
℃で１時間焼結した。After press-molding the raw material powder obtained in this way, 900
Sintered at ℃ for 1 hour.
以上のようにして作製した試料の超電導臨界温度を測定
したところ、各試料■〜■はｌｌ０Ｋ、 １０７に、
１０６ Ｋで急激に抵抗を減じ始め、８１に、８７Ｋ。When the superconducting critical temperatures of the samples prepared as described above were measured, each of the samples ■ to ■ was 10K, 107,
At 106 K, the resistance began to decrease rapidly, to 81, and then to 87 K.
８５Ｋにおいて電気抵抗が検出できなくなった。尚この
臨界温度の測定は、定法に従って試料の両端にＡｇ導電
ペーストにて電極を付け、クライオスタット中での４端
子法によって行った。温度はキャリブレーション済みの
Ａｕ （Ｆｅ）−クロネル熱電対を用いて監視した。ま
た、この試料は、作製後２０日間に亘って空気中に放置
したが、その後に行った再測定に右いても超電導特性に
有意な差は顕れなかった。Electrical resistance became undetectable at 85K. The critical temperature was measured by a four-terminal method in a cryostat, with electrodes made of Ag conductive paste attached to both ends of the sample according to a standard method. Temperature was monitored using a calibrated Au(Fe)-Kronel thermocouple. Furthermore, although this sample was left in the air for 20 days after its preparation, no significant difference in superconducting properties was found even after repeated measurements.
更に、上述のようにして得た試料について、ＩＣＰ（誘
導結合プラズマ発光分光分析装置）にょる分析と重量変
化測定とを併用した組成分析を行ったところ、試料の組
成は
式：Ｔ１２β２ Ｂａ Ｃｕ、 ｏａ
で表すことができ、ａの値は約９．５であった。Furthermore, the composition of the sample obtained as described above was analyzed using ICP (Inductively Coupled Plasma Emission Spectroscopy) and weight change measurement, and the composition of the sample was found to be as follows: T12β2 Ba Cu, It can be expressed as oa, and the value of a was about 9.5.
発明の効果
以上詳述の如く、本発明に従う多元素系複合酸化物超電
導材料は、従来の超電導材料に比較して顕著に高い臨界
温度で超電導体となる。また、この超電導材料は、長期
間に亘って特性が維持される点で、従来の複合酸化物系
超電導材料よりも優れている。Effects of the Invention As detailed above, the multi-element composite oxide superconducting material according to the present invention becomes a superconductor at a significantly higher critical temperature than conventional superconducting materials. Furthermore, this superconducting material is superior to conventional composite oxide-based superconducting materials in that its properties are maintained over a long period of time.
このように、本発明に従えば、安定した高い臨界温度を
有する新規な超電導材料が得られるため、経済的な冷却
設備によって超電導現象を利用することができる。これ
ら本発明に従う超電導材料は、薄板材、細線材あるいは
小部品として、また、スパッタリング等により薄膜とし
て形成することによって、ジョセフソン素子、５ＱＵＩ
Ｄ、超電導磁石、各種センサ等広範な分野に適用できる
。Thus, according to the present invention, a novel superconducting material having a stable and high critical temperature is obtained, so that the superconducting phenomenon can be utilized with economical cooling equipment. These superconducting materials according to the present invention can be formed into Josephson elements, 5QUI
D, can be applied to a wide range of fields such as superconducting magnets and various sensors.
Claims (1)
元素βは周期律表IIａ族から選択されたＢａ以外の元素
であり、ｘ、ｙ、ｚは、それぞれ ０．５≦ｘ≦３．０ ０．５≦ｙ≦３．０ ０．９≦ｚ≦４．０を満たす数である〕 で示される組成を有する複合酸化物を主として含むこと
を特徴とする超電導材料。 （２）第１請求項に記載の超電導材料であって、式：Ｔ
ｌ＿ｘβ＿ｙＢａＣｕ＿ｚＯ＿ａ 〔但し、ｘ、ｙ、ｚは、それぞれ １．５≦ｘ≦２．５ １．５≦ｙ≦２．５ ２．５≦ｚ≦３．５を満たす数である〕 で示される組成を有する複合酸化物を主として含むこと
を特徴とする超電導材料。 （３）第１請求項または第２請求項に記載の超電導材料
を製造する方法であって、前記Ｔｌ、元素β、Ｂａ並び
にＣｕの各単体粉末あるいは該元素のうちの少なくとも
ひとつを含む化合物粉末を、該元素を全て含むように混
合した混合物、あるいは、該混合物を焼成した後に粉砕
して得た焼成体粉末を原料粉末とし、該原料粉末を焼結
する工程を少なくとも１回含むことを特徴とする超電導
材料の製造方法。 （４）第３請求項に記載の超電導材料の製造方法であっ
て、原料粉末、焼結体または焼結体粉末を成形した後に
最終焼結を実施することを特徴とする超電導材料の製造
方法。 （５）第３請求項または第４請求項に記載の超電導材料
の製造方法であって、前記原料粉末が、前記Ｂａ、元素
β、Ｔｌ並びにＣｕの炭酸塩、硫酸塩、硝酸塩または蓚
酸塩を含むことを特徴とする超電導材料の製造方法。 （６）第５請求項に記載の超電導材料の製造方法であっ
て、原料粉末に含まれる炭酸塩、硫酸塩、硝酸塩または
蓚酸塩の混合物を一旦仮焼した後に前記焼結を実施する
ことを特徴とする超電導材料の製造方法。 （７）第３請求項から第６請求項までの何れか１項に記
載の方法によって得られた前記焼成体または焼結体を含
むターゲットを用い、物理蒸着法によって所定の基板上
に薄膜を成長させることを特徴とする超電導薄膜の製造
方法。 （８）第７請求項に記載の方法であって、前記物理蒸着
法がスパッタリング法またはイオンプレーティング法を
含むことを特徴とする超電導薄膜の製造方法。[Claims] Formula (1): Tl_xβ_yBaCu_zO_a [However,
Element β is an element other than Ba selected from Group IIa of the periodic table, and x, y, and z are respectively 0.5≦x≦3.0 0.5≦y≦3.0 0.9≦z ≦4.0] A superconducting material characterized by mainly containing a composite oxide having a composition represented by the following. (2) The superconducting material according to the first claim, which has the formula: T
l_xβ_yBaCu_zO_a [However, x, y, and z are numbers satisfying 1.5≦x≦2.5, 1.5≦y≦2.5, 2.5≦z≦3.5, respectively] A superconducting material characterized by mainly containing a composite oxide. (3) A method for manufacturing the superconducting material according to claim 1 or 2, wherein the individual powders of Tl, element β, Ba, and Cu or compound powders containing at least one of the elements are provided. is mixed to contain all of the elements, or a fired powder obtained by firing and pulverizing the mixture is used as the raw material powder, and the method includes at least one step of sintering the raw material powder. A method for manufacturing a superconducting material. (4) A method for producing a superconducting material according to claim 3, characterized in that final sintering is performed after shaping the raw material powder, sintered body, or sintered body powder. . (5) The method for producing a superconducting material according to claim 3 or 4, wherein the raw material powder contains carbonate, sulfate, nitrate, or oxalate of Ba, element β, Tl, and Cu. A method for producing a superconducting material, comprising: (6) The method for producing a superconducting material according to claim 5, wherein the sintering is performed after once calcining a mixture of carbonate, sulfate, nitrate, or oxalate contained in the raw material powder. A manufacturing method for characteristic superconducting materials. (7) Using the sintered body or a target containing the sintered body obtained by the method according to any one of claims 3 to 6, a thin film is formed on a predetermined substrate by physical vapor deposition. A method for producing a superconducting thin film, which comprises growing a superconducting thin film. (8) The method of manufacturing a superconducting thin film according to claim 7, wherein the physical vapor deposition method includes a sputtering method or an ion plating method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63042698A JPH07102968B2 (en) | 1988-02-25 | 1988-02-25 | Manufacturing method of superconducting material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63042698A JPH07102968B2 (en) | 1988-02-25 | 1988-02-25 | Manufacturing method of superconducting material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01215717A true JPH01215717A (en) | 1989-08-29 |
| JPH07102968B2 JPH07102968B2 (en) | 1995-11-08 |
Family
ID=12643272
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63042698A Expired - Fee Related JPH07102968B2 (en) | 1988-02-25 | 1988-02-25 | Manufacturing method of superconducting material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07102968B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1990015023A1 (en) * | 1989-05-27 | 1990-12-13 | Foundational Juridical Person International Superconductivity Technology Center | Oxide superconductor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01208325A (en) * | 1988-02-15 | 1989-08-22 | Seiko Epson Corp | Superconductive material |
-
1988
- 1988-02-25 JP JP63042698A patent/JPH07102968B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01208325A (en) * | 1988-02-15 | 1989-08-22 | Seiko Epson Corp | Superconductive material |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1990015023A1 (en) * | 1989-05-27 | 1990-12-13 | Foundational Juridical Person International Superconductivity Technology Center | Oxide superconductor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07102968B2 (en) | 1995-11-08 |
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