JP3034267B2 - Oxide superconductor - Google Patents
Oxide superconductorInfo
- Publication number
- JP3034267B2 JP3034267B2 JP2036912A JP3691290A JP3034267B2 JP 3034267 B2 JP3034267 B2 JP 3034267B2 JP 2036912 A JP2036912 A JP 2036912A JP 3691290 A JP3691290 A JP 3691290A JP 3034267 B2 JP3034267 B2 JP 3034267B2
- Authority
- JP
- Japan
- Prior art keywords
- oxide superconductor
- current density
- critical current
- oxide
- magnetic field
- 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.)
- Expired - Lifetime
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Classifications
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- 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
Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、Bi系やTl系の酸化物超電導体に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a Bi-based or Tl-based oxide superconductor.
（従来の技術） 1986年にBa−La−Cu−Ｏ系の層状プロブスカイト型の
酸化物が40K以上の高い臨界温度を有することが発表さ
れて以来、酸化物系の超電導体が注目を集め、新材料検
索の研究が活発に行われている。その中でも、液体窒素
温度以上の高い臨界温度を有するＹ−Ba−CU−Ｏ系で代
表される欠陥ペロブスカイト型の酸化物超電導体や、Bi
−Sr−Ca−Cu−Ｏ系およびTl−Ba−Ca−Cu−Ｏ系の酸化
物超電導体は、冷媒として高価な液体ヘリウムに代え
て、安価な液体窒素を利用できるため、工業的にも重要
な価値を有している。(Prior art) Since 1986, it was announced that Ba-La-Cu-O-based layered provskite-type oxides have a high critical temperature of 40K or more, oxide-based superconductors have attracted attention. Research on new material search is being actively conducted. Among them, a defective perovskite-type oxide superconductor represented by a Y-Ba-CU-O system having a high critical temperature higher than the temperature of liquid nitrogen,
-Sr-Ca-Cu-O-based and Tl-Ba-Ca-Cu-O-based oxide superconductors can use inexpensive liquid nitrogen instead of expensive liquid helium as a refrigerant, so It has significant value.
特に、Bi系やTl系の酸化物超電導体は、Ｙ系の酸化物
超電導体に比べてさらに臨界温度が高く、液体窒素によ
って冷却を行う際に実用上充分な熱的マージンがとれる
ばかりでなく、高価な希土類元素が不要であること、水
分に対する化学的安定性が高いこと、酸素が抜けにくい
ことなどの利点があり、より優れた酸化物超電導体とし
て注目を集めている。これらの系の酸化物超電導体は、
Ｙ−Ba−Cu−Ｏ系の酸化物超電導体などと同様に結晶性
の酸化物であるため、通常のセラミックス材料と同様に
焼成法を用いて各種部材化することが試みられている。In particular, Bi-based and Tl-based oxide superconductors have a higher critical temperature than Y-based oxide superconductors, and not only can a practically sufficient thermal margin be obtained when cooling with liquid nitrogen. Oxide superconductors have attracted attention as superior oxide superconductors because they have the advantages of not requiring expensive rare earth elements, having high chemical stability against moisture, and being difficult to release oxygen. The oxide superconductors of these systems are:
Since it is a crystalline oxide like a Y-Ba-Cu-O-based oxide superconductor or the like, it has been attempted to form various members using a firing method in the same manner as a normal ceramic material.
（発明が解決しようとする課題） ところで、上述したような通常の焼成法によって得た
Bi系やTl系の酸化物超電導体の臨界電流密度を高めるた
めには、有効なピンニングセンターを導入することが必
要とされている。(Problems to be Solved by the Invention) By the way, it is obtained by the usual firing method as described above.
To increase the critical current density of Bi-based and Tl-based oxide superconductors, it is necessary to introduce an effective pinning center.
しかしながら、これらの酸化物超電導体は、Ｙ−Ba−
Cu−Ｏ系と同様の層状ペロブスカイト構造を持ってお
り、臨界電流密度に有効なピンニングセンターのサイズ
を決定するコヒーレンス長が著しく短いことが知られて
いる。そしてこのことは、従来の金属系超電導体で有効
なピンニングセンターとして知られている常伝導析出物
などは、サイズ的に酸化物超電導体では有効なピンニン
グセンターとなり得ないことを示唆している。However, these oxide superconductors are Y-Ba-
It has a layered perovskite structure similar to that of the Cu-O system, and it is known that the coherence length that determines the size of the pinning center effective for the critical current density is extremely short. This suggests that normal conductive precipitates and the like, which are known as effective pinning centers in conventional metal-based superconductors, cannot be effective pinning centers in oxide superconductors in terms of size.
本発明は、このような従来技術の課題に対処するため
になされたもので、超電導部材として実用化する際に重
要な臨界電流密度に対する外部磁場の影響を極力排除し
た臨界電流密度の高い酸化物超電導体を提供することを
目的としている。The present invention has been made in order to address such problems of the prior art, and has an oxide having a high critical current density that eliminates as much as possible the influence of an external magnetic field on the critical current density that is important when put to practical use as a superconducting member. The purpose is to provide a superconductor.
［発明の構成］ （課題を解決するための手段） 本発明の酸化物超電導体は、 化学式:Aa2Ma3Cu2Ow ……（Ｉ） または Aa2Ma4Cu3Ow ……（II） （式中、AaはBiおよびTlから選ばれた１種の元素を、Ma
はSr、CaおよびBaから選ばれた２種以上の元素の組合せ
をを表し、ｗは酸素量を表し、化学量論比からのある程
度のずれを許容する。たとえば（Ｉ）式では、ｗ＝10＋
δ（δ＝−0.2〜0.4）、（II）式では、ｗ＝８＋δ（δ
＝−0.2〜0.4）である。ただし、Aaの一部はPbおよびSb
から選ばれた少なくとも１種の元素で置換可能。以下同
じ。） もしくは、 化学式:AbMb4Cu3Ow ……（III） または AbMb3Cu2Ow ……（IV） （式中、AbはTlを、MbはCaおよびBaの組合せを表す。た
だし、Abの一部はPbおよびSbから選ばれた少なくとも１
種の元素で置換可能。以下同じ。） で実質的に示される酸化物超電導体であって、その結晶
中に構成陽イオンの空孔を含むことを特徴とするもので
ある。[Constitution of the Invention] (Means for Solving the Problems) The oxide superconductor of the present invention has a chemical formula: Aa 2 Ma 3 Cu 2 Ow (I) or Aa 2 Ma 4 Cu 3 Ow (II) (Where Aa represents one element selected from Bi and Tl,
Represents a combination of two or more elements selected from Sr, Ca and Ba, w represents the amount of oxygen, and allows a certain deviation from the stoichiometric ratio. For example, in equation (I), w = 10 +
δ (δ = −0.2 to 0.4), in equation (II), w = 8 + δ (δ
= −0.2 to 0.4). However, part of Aa is Pb and Sb
Can be replaced with at least one element selected from same as below. Or the chemical formula: AbMb 4 Cu 3 Ow (III) or AbMb 3 Cu 2 Ow (IV) (where Ab represents Tl and Mb represents a combination of Ca and Ba. The part is at least one selected from Pb and Sb
Can be replaced with some elements. same as below. ) An oxide superconductor substantially represented by the formula (1), characterized in that its crystal contains vacancies of constituent cations.
すなわち本発明の酸化物超電導体は、上記（Ｉ）式〜
（IV）式で示される超電導構造を保ちつつ、陽イオンの
欠損を有するものであり、導入された構成陽イオン空
孔、もしくはそのクラスターはピンニングセンターとし
て機能するものである。That is, the oxide superconductor of the present invention has the above formula (I)
It has a cation deficiency while maintaining the superconducting structure represented by the formula (IV), and the introduced constituent cation vacancy or cluster thereof functions as a pinning center.
上記構成陽イオン空孔は、１化学式当り0.01〜1.0個
（空孔総数）の場合で存在させることが好ましい。ただ
し、（Ｉ）式で示される酸化物超導電体において、Ma元
素単独で陽イオン空孔を形成する際には、１化学式当り
0.01〜0.4個の範囲、またAa元素またはCu単独で陽イオ
ン空孔を形成する際には、それぞれ0.01〜0.8個の範囲
とすることが好ましい。また、（II）、（III）式およ
び（IV）式で示される酸化物超電導体において、１種の
陽イオン元素単独で空孔を形成する際には、それぞれ0.
01〜0.5個の範囲とするすることが好ましい。The constituent cation vacancies are preferably present in the case of 0.01 to 1.0 (the total number of vacancies) per chemical formula. However, in the oxide superconductor represented by the formula (I), when the cation vacancy is formed by the Ma element alone,
In the case where the cation vacancies are formed with the Aa element or Cu alone, the range is preferably 0.01 to 0.8, respectively. In addition, in the oxide superconductors represented by the formulas (II), (III) and (IV), when one kind of cation element alone forms vacancies, each of the cations has a thickness of 0.1.
It is preferable to set the range of 01 to 0.5.
構成陽イオン空孔の数を上記範囲とするのは、これら
の陽イオン空孔の数が１化学式当り0.01個に達しない
と、ピンニングセンターの数が少なく充分な効果が得ら
れず、また上述の数値上限のいずれかを超えると超電導
相以外の相が析出し、超導電特性に悪影響を及ぼすため
である。これら陽イオンは、上記範囲内で欠損を生じさ
せることが好ましく、これによってより安定して臨界電
流密度の向上が図れる。If the number of constituent cation vacancies is within the above range, unless the number of these cation vacancies reaches 0.01 per chemical formula, the number of pinning centers is small and sufficient effect cannot be obtained. If any one of the numerical upper limits is exceeded, a phase other than the superconducting phase is precipitated, which adversely affects the superconducting properties. It is preferable that these cations cause defects within the above range, whereby the critical current density can be more stably improved.
本発明の酸化物超電導体は、たとえば以下のように作
製される。The oxide superconductor of the present invention is produced, for example, as follows.
まず、Bi、Tl、Pb、Sb、Sr、Ca、Baの単体または化合
物を各元素の出発原料として用いる。これら構成元素の
化合物としては、炭酸塩や酸化物を用いることができる
他に、炭酸塩以外の加熱により酸化物に転化する硝酸
塩、水酸化物など、さらには有機酸塩、有機性金属など
を用いてもよい。First, a simple substance or a compound of Bi, Tl, Pb, Sb, Sr, Ca, and Ba is used as a starting material for each element. As the compounds of these constituent elements, carbonates and oxides can be used, as well as nitrates and hydroxides which are converted to oxides by heating other than carbonates, as well as organic acid salts and organic metals. May be used.
これら構成元素の出発原料は、本来上記（Ｉ）式〜
（IV）式のいずれかの式を満足するよう混合するもので
あるが、本発明の酸化物超電導体においては、陽イオン
空孔の数が上記した範囲となるように、構成陽イオンの
いずれかを上記化学式の原子比から減少させて混合する
か、あるいは構成陽イオンのいずれかを上記化学式の原
子比から増量し、相対的に陽イオン空孔が形成されるよ
う混合する。たとえば、（Ｉ）式においてMa元素を化学
量論比から0.1〜0.6個の範囲で増やして原料組成物を作
製することにより、Aa元素とCuについて同時に0.01〜0.
4個の範囲で欠損を形成することができる。The starting materials of these constituent elements are originally represented by the above formula (I).
Although mixing is performed so as to satisfy any one of the formulas (IV), in the oxide superconductor of the present invention, any one of the constituent cations is selected so that the number of the cation vacancies is in the above range. The amount of the constituent cations is reduced from the atomic ratio of the above chemical formula, or the amount of any of the constituent cations is increased from the atomic ratio of the above chemical formula, and mixed so that cation vacancies are relatively formed. For example, in the formula (I), by increasing the amount of the Ma element from the stoichiometric ratio in the range of 0.1 to 0.6 to prepare the raw material composition, the Aa element and the Cu are simultaneously adjusted to 0.01 to 0.
Defects can be formed in four ranges.
そして、上記原料組成物を必要に応じて800℃程度の
温度で仮焼した後、成形、焼結を行うことにより、上記
範囲の陽イオン空孔を有する酸化物超電導体が得られ
る。The raw material composition is calcined, if necessary, at a temperature of about 800 ° C., and then molded and sintered to obtain an oxide superconductor having cationic vacancies in the above range.
また、スパッタ法、蒸着法、CVD法などの薄膜形成法
を利用する際には、上記範囲の陽イオン空孔が形成され
るよう飛翔粒子数を制御することによって、同様に陽イ
オン空孔を有する酸化物超電導体が得られるなど、各種
製造方法の適用が可能である。Also, when using a thin film forming method such as sputtering, vapor deposition, or CVD, the number of flying particles is controlled so that cation vacancies in the above range are formed. Various manufacturing methods can be applied, such as obtaining an oxide superconductor having the same.
さらに、陽イオン空孔の導入方法としては、原料組成
物は化学式に基いて調整し、焼結させた後に、高エネル
ギー粒子線などを照射することによって、結晶中に欠損
を形成する方法を適用することも可能である。Furthermore, as a method for introducing cation vacancies, a method is used in which a raw material composition is adjusted based on a chemical formula, sintered, and then irradiated with a high-energy particle beam or the like to form a defect in the crystal. It is also possible.
（作 用） 本発明の酸化物超電導体は、超電導状態を実現し得る
結晶構造を満足しつつ、結晶中に構成陽イオンの空孔を
有するものである。このような構成陽イオン空孔はÅオ
−ダで存在する。そして、このような陽イオン空孔がサ
イズ的に酸化物超電導体の結晶中でフラックスのピンニ
ングセンターとして有効に機能するため、磁場中におい
ても臨界電流密度の低下が抑制される。(Operation) The oxide superconductor of the present invention has a crystal structure capable of realizing a superconducting state and has pores of constituent cations in the crystal. Such constituent cation vacancies exist on the order. And since such a cationic vacancy effectively functions as a flux pinning center in the crystal of the oxide superconductor in size, a decrease in critical current density is suppressed even in a magnetic field.
（実施例） 次に、本発明の実施例について説明する。(Example) Next, an example of the present invention is described.
実施例１〜５、比較例１ 化学式:Bi2（Sr,Ca）3-xCu2Ow を満足するように、Bi2O3、SrCO3、CaCO3、CuOの各粉末
を所定量秤量し、これを充分に混合した後、この混合粉
末をアルミナ製るつぼ中に収容して、空気中において80
0℃×８時間の条件で仮焼し、この仮焼物をボールミル
で粉砕して、平均粒径２μｍのBi−Sr−Ca−Cu−Ｏ系酸
化物超電導体粉末を作製した。なお、上記式中のｘの値
は、第１表に示すように、５種類の値をそれぞれ採用
し、各々について酸化物超電導体粉末を作製した。また
比較例１として、上記ｘの値を０としたものについても
同様にして作製した。Examples 1 to 5 and Comparative Example 1 A predetermined amount of each powder of Bi 2 O 3 , SrCO 3 , CaCO 3 and CuO was weighed so as to satisfy the chemical formula: Bi 2 (Sr, Ca) 3-x Cu 2 Ow. After thoroughly mixing the mixture, the mixed powder was placed in an alumina crucible and allowed to stand in air for 80 minutes.
The calcined product was calcined at 0 ° C. for 8 hours, and the calcined product was pulverized with a ball mill to prepare a Bi—Sr—Ca—Cu—O-based oxide superconductor powder having an average particle size of 2 μm. As shown in Table 1, five values of x in the above formula were adopted, and an oxide superconductor powder was produced for each of the five values. In addition, as Comparative Example 1, a device in which the value of x was set to 0 was similarly manufactured.
次に、これらBi−Sr−Ca−Cu−Ｏ系酸化物超電導体粉
末をそれぞれ用い、プレス成形法によって500kg/cm2の
プレス条件で直径20mm×厚さ3mmの成形体を作製し、こ
の成形体を空気中において830℃×８時間の条件で焼成
してBi−Sr−Ca−Cu−Ｏ系酸化物超電導焼結体を得た。Then, using these Bi-Sr-Ca-Cu- O based oxide superconductor powder, respectively, by press molding at a press conditions of 500 kg / cm 2 to prepare a molded body having a diameter of 20 mm × a thickness of 3 mm, the molding The body was fired in air at 830 ° C. for 8 hours to obtain a Bi—Sr—Ca—Cu—O-based oxide superconducting sintered body.
このようにして得た酸化物超電導焼結体の相対密度を
測定したところ、98％と良好な値を有していた。また、
４端子法で電気抵抗率の温度特性を測定し、これから得
た臨界温度を第１表に示す。また、4.2Kにおいて零磁場
中での臨界電流密度と、1Tの磁場中での臨界電流密度と
を測定し、得られた臨界電流密度値から零磁場中での臨
界電流密度Jcに対する1Tの磁場中でのそれの比（Jc（1
T）/JC（０））も併せて示す。When the relative density of the oxide superconducting sintered body thus obtained was measured, it was 98%, which was a good value. Also,
The temperature characteristics of the electrical resistivity were measured by the four-terminal method, and the critical temperatures obtained therefrom are shown in Table 1. The critical current density in a zero magnetic field at 4.2K and the critical current density in a 1T magnetic field were measured.From the obtained critical current density value, the 1T magnetic field with respect to the critical current density Jc in the zero magnetic field was obtained. Its ratio in (Jc (1
T) / JC (0)) is also shown.
第１表から明らかなように、これらの実施例による酸
化物超電導体は、いずれも磁場中での臨界電流密度の低
下の小さな優れた超電導体であることが分る。 As is clear from Table 1, the oxide superconductors according to these examples are all excellent superconductors with a small decrease in critical current density in a magnetic field.
実施例６、比較例２ Bi1.8Pb0.2Sr1.8Ca2.0Cu3.0Ow を満足するように、Bi2O3、PbO、SrCO3、CaCO3、CuOの
各粉末を所定量秤量し、これを充分に混合して混合粉末
（実施例６）を作製した。Example 6, Comparative Example 2 A predetermined amount of each powder of Bi 2 O 3 , PbO, SrCO 3 , CaCO 3 , and CuO was weighed so as to satisfy Bi 1.8 Pb 0.2 Sr 1.8 Ca 2.0 Cu 3.0 O w. The mixture was sufficiently mixed to prepare a mixed powder (Example 6).
また、本発明との比較として、 Bi1.8Pb0.2Sr2.0Ca2.0Cu3.0Ow を満足するように上記各粉末を混合したもの（比較例
２）を作製した。Further, as a comparison with the present invention, a mixture (Comparative Example 2) in which each of the above powders was mixed so as to satisfy Bi 1.8 Pb 0.2 Sr 2.0 Ca 2.0 Cu 3.0 O w was prepared.
これらの混合粉末をそれぞれ用いて成形体を作製し、
845℃×100時間の条件で大気中で焼結して酸化物超電導
焼結体を作製した。A molded body is produced using each of these mixed powders,
Sintering was performed in air at 845 ° C. for 100 hours to produce an oxide superconducting sintered body.
こうして得た焼結体を用いて、それぞれ臨界温度およ
び77Kでの臨界電流密度を磁場中で測定したところ、臨
界温度は実施例６が105K、比較例２が110Kであった。ま
た、それぞれの臨界電流密度の磁場依存性を第１図に示
す。Using the thus obtained sintered body, the critical temperature and the critical current density at 77 K were measured in a magnetic field, and the critical temperature was 105 K in Example 6 and 110 K in Comparative Example 2. FIG. 1 shows the magnetic field dependence of each critical current density.
同図から明らかなように、この実施例の酸化物超電導
体は、磁場中での臨界電流密度の低下が少ないのに対
し、比較例による酸化物超電導体は5T前後まで急激に臨
界電流密度が低下していることが分る。As is clear from the figure, the oxide superconductor of this example has a small decrease in critical current density in a magnetic field, whereas the oxide superconductor of the comparative example has a critical current density sharply up to about 5 T. You can see that it has dropped.
実施例７、比較例３ Tl2Ba2Ca1.8Cu3Ow を満足するように、Tl2O3、BaCO3、CaCO3、CuOの各粉末
を所定量秤量し、これを充分混合して混合粉末（実施例
７）を作製した。Example 7, Comparative Example 3 A predetermined amount of each powder of Tl 2 O 3 , BaCO 3 , CaCO 3 , and CuO was weighed so as to satisfy Tl 2 Ba 2 Ca 1.8 Cu 3 O w, and these were thoroughly mixed. A mixed powder (Example 7) was produced.
また本発明との比較として、 Tl2Ba2Ca2Cu2Ow を満足するように上記各粉末を混合したもの（比較例
３）を作製した。As a comparison with the present invention, a mixture (Comparative Example 3) was prepared by mixing the above powders so as to satisfy Tl 2 Ba 2 Ca 2 Cu 2 O w .
これらの混合粉末をそれぞれ用いて成形体を作製し、
880℃×30分間の条件で酸素フロー中で焼成して焼結体
を得た。A molded body is produced using each of these mixed powders,
It was fired in an oxygen flow at 880 ° C. for 30 minutes to obtain a sintered body.
このようにして得た焼結体の臨界温度および77Kにお
ける1Tでの臨界電流密度と0Tでの臨界電流密度との比を
測定したところ、第２表に示す結果が得られた。The critical temperature of the sintered body thus obtained and the ratio of the critical current density at 1 T at 77 K to the critical current density at 0 T were measured. The results shown in Table 2 were obtained.
このように本発明によれば磁場中での臨界電流密度の
低下を抑えることができる。 As described above, according to the present invention, a decrease in critical current density in a magnetic field can be suppressed.
実施例８、比較例４ Tl1Ba2Ca1.8Cu3Ow を満足するように、Tl2O3、BaCO3、CaCO3、CuOの各粉末
を所定量秤量し、これを充分混合して混合粉末（実施例
８）を作製した。Example 8, Comparative Example 4 Tl 2 O 3 , BaCO 3 , CaCO 3 , and CuO powders were weighed to a predetermined amount so as to satisfy Tl 1 Ba 2 Ca 1.8 Cu 3 O w, and these were thoroughly mixed. A mixed powder (Example 8) was produced.
また本発明との比較として、 Tl1Ba2Ca2Cu3Ow を満足するように上記各粉末を混合したもの（比較例
４）を作製した。As a comparison with the present invention, a mixture (Comparative Example 4) was prepared by mixing the above powders so as to satisfy Tl 1 Ba 2 Ca 2 Cu 3 O w .
これらの混合粉末をそれぞれ用いて成形体を作製し、
950℃×30分間の条件で酸素フロー中で焼成して焼結体
を得た。A molded body is produced using each of these mixed powders,
It was fired in an oxygen flow at 950 ° C. for 30 minutes to obtain a sintered body.
このようにして得た焼結体の臨界温度および77Kにお
ける1Tでの臨界電流密度と0Tでの臨界電流密度との比を
測定したところ、第３表に示す結果が得られた。When the critical temperature and the ratio of the critical current density at 1 T at 77 K and the critical current density at 0 T of the sintered body thus obtained were measured, the results shown in Table 3 were obtained.
このように本発明によれば磁場中での臨界電流密度の
低下を抑えることができる。 As described above, according to the present invention, a decrease in critical current density in a magnetic field can be suppressed.
実施例９、比較例５ Tl1Ba2Ca0.8Cu3Ow を満足するように、Tl2O3、BaCO3、CaCO3、CuOの各粉末
を所定量秤量し、これを充分混合して混合粉末（実施例
９）を作製した。Example 9, Comparative Example 5 Tl 2 O 3 , BaCO 3 , CaCO 3 , and CuO powders were weighed in predetermined amounts so as to satisfy Tl 1 Ba 2 Ca 0.8 Cu 3 O w, and these were thoroughly mixed. A mixed powder (Example 9) was produced.
また本発明との比較として、 Tl1Ba2Ca1Cu3Ow を満足するように上記各粉末を混合したもの（比較例
５）を作製した。As a comparison with the present invention, a mixture (Comparative Example 5) was prepared by mixing the above powders so as to satisfy Tl 1 Ba 2 Ca 1 Cu 3 O w .
これらの混合粉末をそれぞれ用いて成形体を作製し、
950℃×30分間の条件で酸素フロー中で焼成して焼結体
を得た。A molded body is produced using each of these mixed powders,
It was fired in an oxygen flow at 950 ° C. for 30 minutes to obtain a sintered body.
このようにして得た焼結体の臨界温度および77Kにお
ける1Tでの臨界電流密度と0Tでの臨界電流密度との比を
測定したところ、第４表に示す結果が得られた。The critical temperature of the sintered body thus obtained and the ratio of the critical current density at 1 T at 77 K to the critical current density at 0 T were measured. The results shown in Table 4 were obtained.
このように本発明によれば磁場中での臨界電流密度の
低下を抑えることができる。 As described above, according to the present invention, a decrease in critical current density in a magnetic field can be suppressed.
［発明の効果］ 以上の実施例からも明らかなように、本発明による酸
化物超電導体は、磁場中で臨界電流密度の低下が少な
く、実用的なものとなる。[Effects of the Invention] As is clear from the above examples, the oxide superconductor according to the present invention is practical with little decrease in critical current density in a magnetic field.
第１図は本発明の一実施例による酸化物超電導体の臨界
電流密度の磁場依存性を従来例と比較して示す図であ
る。FIG. 1 is a diagram showing the magnetic field dependence of the critical current density of an oxide superconductor according to one embodiment of the present invention, as compared with a conventional example.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 安藤 健 神奈川県川崎市幸区小向東芝町１番地 株式会社東芝総合研究所内 (56)参考文献 特開 平２−59466（ＪＰ，Ａ) 特開 平３−242366（ＪＰ，Ａ) 特開 平１−242421（ＪＰ，Ａ) 特開 平１−226737（ＪＰ，Ａ) 特開 平２−227911（ＪＰ，Ａ) 特開 平３−222213（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C01G 1/00 ＣＡ（ＳＴＮ) ＲＥＧＩＳＴＲＹ（ＳＴＮ)────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Ken Ando 1 Koga Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Research Institute, Inc. (56) References JP-A-2-59466 (JP, A) JP-A-3-242366 (JP, A) JP-A-1-242421 (JP, A) JP-A-1-226737 (JP, A) JP-A-2-227911 (JP, A) JP-A-3-222213 (JP) , A) (58) Fields studied (Int. Cl. 7 , DB name) C01G 1/00 CA (STN) REGISTRY (STN)
Claims (2)
はSr、CaおよびBaから選ばれた２種以上の元素を組合せ
を表す。ただし、Aaの一部はPbおよびSbから選ばれた少
なくとも１種の元素で置換可能。） もしくは、 化学式:AbMb4Cu3Ow ……（III） またはAbMb3Cu2Ow ……（IV） （式中、AbはTlを、MbはCaおよびBaの組合せを表す。た
だし、Abの一部はPbおよびSbから選ばれた少なくとも１
種の元素で置換可能。） で実質的に示される酸化物超電導体であって、 その結晶中に構成陽イオンの空孔を含むことを特徴とす
る酸化物超電導体。1. A chemical formula: Aa 2 Ma 3 Cu 2 Ow (I) or Aa 2 Ma 4 Cu 3 Ow (II) (wherein, Aa represents one element selected from Bi and Tl) , Ma
Represents a combination of two or more elements selected from Sr, Ca and Ba. However, part of Aa can be replaced with at least one element selected from Pb and Sb. Or chemical formula: AbMb 4 Cu 3 Ow (III) or AbMb 3 Cu 2 Ow (IV) (where Ab represents Tl and Mb represents a combination of Ca and Ba. The part is at least one selected from Pb and Sb
Can be replaced with some elements. ) An oxide superconductor substantially represented by the formula: wherein the crystal contains vacancies of constituent cations in its crystal.
（ただし、前記（Ｉ）式において、Ma単独空孔の場合は
0.01〜0.4個、AaまたはCu単独空孔の場合は0.01〜0.8
個、また前記（II）式、（III）式および（IV）式にお
いて、１種の陽イオン単独の空孔の場合は0.01〜0.5
個）の割合で存在していることを特徴とする酸化物超電
導体。2. The oxide superconductor according to claim 1, wherein the number of constituent cation vacancies is 0.01 to 1.0 per chemical formula.
0.01 to 0.4, 0.01 to 0.8 for Aa or Cu single holes
In the above formulas (II), (III) and (IV), in the case of a single cation-only vacancy, 0.01 to 0.5
Oxide superconductor which is present at a ratio of
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2036912A JP3034267B2 (en) | 1990-02-17 | 1990-02-17 | Oxide superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2036912A JP3034267B2 (en) | 1990-02-17 | 1990-02-17 | Oxide superconductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03242365A JPH03242365A (en) | 1991-10-29 |
| JP3034267B2 true JP3034267B2 (en) | 2000-04-17 |
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ID=12482984
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2036912A Expired - Lifetime JP3034267B2 (en) | 1990-02-17 | 1990-02-17 | Oxide superconductor |
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| Country | Link |
|---|---|
| JP (1) | JP3034267B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100772014B1 (en) * | 2006-07-14 | 2007-10-31 | 한국전기연구원 | Fabrication method of high temperature superconducting film using assisted cluster beam, fabrication apparatus, and the high temperature superconducting film |
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1990
- 1990-02-17 JP JP2036912A patent/JP3034267B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03242365A (en) | 1991-10-29 |
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