JP2789118B2 - Oxide superconductor and manufacturing method thereof - Google Patents
Oxide superconductor and manufacturing method thereofInfo
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- JP2789118B2 JP2789118B2 JP1308618A JP30861889A JP2789118B2 JP 2789118 B2 JP2789118 B2 JP 2789118B2 JP 1308618 A JP1308618 A JP 1308618A JP 30861889 A JP30861889 A JP 30861889A JP 2789118 B2 JP2789118 B2 JP 2789118B2
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- temperature
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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】 ［産業上の利用分野］ 本発明は高い臨界温度（Tce）を有するBi−Sr−Ca−C
u−Ｏ系酸化物超電導体およびその製造方法に関する。The present invention relates to a Bi-Sr-Ca-C having a high critical temperature (Tce).
The present invention relates to a u-O-based oxide superconductor and a method for producing the same.
［従来技術］ 現在、超電導体としては、NbTi,Nb3Snで代表される金
属系超電導体が使用されているが、これらの臨界温度Tc
（超電導状態になる温度）は20K程度であったが、近年
に至り、Physical Review.Letters58（1978）pp908−91
0に於いて77K以上で超電導現象を示す遷移金属、アルカ
リ土類元素、銅から成る複合酸化物が報告され、高価な
液体ヘリウムに換わり、安価な液体窒素温度での使用が
可能となり、その用途が大きく拡がる傾向にある。PRIOR ART At present, as a superconductor, NbTi, a metal based superconductor which is represented by Nb 3 Sn is used, these critical temperatures Tc
The temperature at which the superconducting state is reached was about 20K, but recently, Physical Review. Letters 58 (1978) pp908-91
A composite oxide composed of a transition metal, alkaline earth element, and copper that exhibits superconductivity at 77K or higher at 0K has been reported, and can be used at a low temperature of liquid nitrogen instead of expensive liquid helium. Tend to greatly expand.
このような酸化物超電導体に対しては、その臨界温度
Tcをさらに高める研究がなされ、最近に至っては、Jap.
J.Appl.Letters27（1988）L209において臨界温度Tcが11
0Kあるいは80KのBi−Sr−Ca−Cu−Ｏ系超電導酸化物が
報告され、注目を集めるところとなった。For such an oxide superconductor, its critical temperature
Research has been conducted to further increase Tc, and recently, Jap.
J. Appl. Letters 27 (1988) Critical temperature Tc is 11 in L209
A superconducting oxide of Bi-Sr-Ca-Cu-O system at 0K or 80K has been reported and attracted attention.
［発明が解決しようとする問題点］ しかしながら、上記Bi−Sr−Ca−Cu−Ｏ系超電導体を
焼結体（バルク体）として製造する場合、焼結体中に臨
界温度Tcが110K相と80K相が混在し、80K相が不純物的挙
動を示すために焼結体自体のTcを高めることができない
という問題点があった。[Problems to be Solved by the Invention] However, when the above Bi-Sr-Ca-Cu-O-based superconductor is manufactured as a sintered body (bulk body), the critical temperature Tc in the sintered body is 110K phase. There is a problem that the Tc of the sintered body itself cannot be increased because the 80K phase is mixed and the 80K phase exhibits an impurity-like behavior.
因みに、現在知られているこれらの相は 110K相がBi2Sr2Ca2Cu3O10＋δ 80K相がBi2Sr2Ca1Cu2O８＋δ とされている。By the way, among these phases which are currently known, the 110K phase is Bi 2 Sr 2 Ca 2 Cu 3 O 10 + δ The 80K phase is Bi 2 Sr 2 Ca 1 Cu 2 O 8 + δ .
この110K相を単相化する技術としては、Jap.J.Appl.P
hys Vo127,No.6（1988）L 1041−1043において高野らが
Pbを添加することにより、110K相の含有量を高めること
が報告されている。ところが、Pb添加によれば、粒界に
安定なCa2PbO4が生成し、超電導特性が低下するという
欠点を有する。As a technology to convert this 110K phase into a single phase, Jap.J.Appl.P
hyos Vo127, No.6 (1988) L 1041-1043
It has been reported that the addition of Pb increases the content of the 110K phase. However, the addition of Pb has a drawback that stable Ca 2 PbO 4 is generated at the grain boundary, and the superconductivity is deteriorated.
［問題点を解決するための手段］ 本発明者等は上記点に対し、研究を重ねた結果、特定
比率から成るBi−Pb−Sr−Ca−Cu−Ｏ系組成物に対し、
Na,Liの化合物を特定の割合で添加することによって焼
結温度を低くすることができるとともに、Ca2PbO4の生
成を抑制しつつ、110K相の生成を促進し、110Kの含有率
の高い高臨界温度を有する酸化物超電導体が提供できる
ことを知見した。[Means for Solving the Problems] The present inventors have conducted repeated studies on the above points, and as a result, with respect to a Bi-Pb-Sr-Ca-Cu-O-based composition having a specific ratio,
By adding Na and Li compounds in a specific ratio, the sintering temperature can be lowered, and while suppressing the production of Ca 2 PbO 4 , the production of the 110K phase is promoted, and the content of 110K is high. It has been found that an oxide superconductor having a high critical temperature can be provided.
即ち、本発明の酸化物超電導体は製造方法としてはそ
の構成物としてBi,Pb,Sr,Ca,Cu,とNa,Liの少なくともい
ずれかからなる複合酸化物から成り、これらの各金属元
素のモル比率が、Srのモル数を２とした時に、Biが1.8
乃至2.2、Pbが0.1乃至0.6、Caが2.0乃至3.5、Cuが3.0乃
至4.5、NaとLiが合量で0.01乃至0.5の割合から成る成形
体を酸素含有雰囲気で820乃至850℃の温度で焼成するこ
とを特徴とするもので、得られる超電導体の組成を構成
金属成分のモル比率において、Srのモル数を２とした時
に、Biが1.8乃至2.2、Pbが0.1乃至0.5、Caが2.0乃至3.
5、Cuが3.0乃至4.5、NaとLiが合量で0.01以下の割合と
することによって臨界温度（Tc）100K以上が達成できる
ものである。That is, the oxide superconductor of the present invention is composed of a composite oxide composed of at least one of Bi, Pb, Sr, Ca, Cu, and Na or Li as a constituent of the production method. When the molar ratio is 2 with the number of moles of Sr, Bi is 1.8
To 2.2, Pb is 0.1 to 0.6, Ca is 2.0 to 3.5, Cu is 3.0 to 4.5, and a compact comprising Na and Li in a total amount of 0.01 to 0.5 is fired in an oxygen-containing atmosphere at a temperature of 820 to 850 ° C. The composition of the resulting superconductor in the molar ratio of the constituent metal components, when the number of moles of Sr is 2, Bi is 1.8 to 2.2, Pb is 0.1 to 0.5, and Ca is 2.0 to 2.0. 3.
5. A critical temperature (Tc) of 100 K or more can be achieved by setting the ratio of Cu to 3.0 to 4.5 and the total amount of Na and Li to 0.01 or less.
以下、本発明を詳述する。 Hereinafter, the present invention will be described in detail.
本発明における特徴の一つは、製法上、成形体組成を
複合酸化物として存在する各金属元素のモル比率を特定
の範囲、即ちSrのモル数を２とした時、Biが1.8乃至2.
2、Caが2.0乃至3.5、Cuが3.0乃至4.5の割合とし、且つ
この系に体し、Sr＝２に対し、Pbを0.1乃至0.6、NaとLi
が合量で0.01乃至0.5の割合に調製する点にある。Pbの
添加効果は先行技術に記載の通り、110K相の生成を促進
することができるが、Pbの添加によってCa2PbO4の不純
物が生成され、特性を逆に劣化させてしまう。そこで、
NaあるいはLiを添加することによって焼成温度を低く
し、下記式 2Bi2Sr2Ca1Cu2Oy→Bi2Sr2Ca2Cu3Oy′ ＋Bi2Sr2CuOy″ で示される反応によって焼結過程で生成された80K相の
超電導体の110K相の超電導体への変換を促進するととも
にCa2PbO4 の生成を抑制し、焼結体の粒界析出物の影響
を低減することができる。One of the features of the present invention is that, in terms of the production method, when the molar ratio of each metal element present as a composite oxide in a molded body composition is in a specific range, that is, when the number of moles of Sr is 2, Bi is 1.8 to 2.
2, Ca is 2.0 to 3.5, Cu is 3.0 to 4.5, and in this system, Sr = 2, Pb is 0.1 to 0.6, Na and Li
Is that the total amount is adjusted to 0.01 to 0.5. As described in the prior art, the effect of the addition of Pb can promote the formation of the 110K phase, but the addition of Pb generates impurities of Ca 2 PbO 4 , which in turn deteriorates the characteristics. Therefore,
The sintering temperature is lowered by adding Na or Li, and the sintering process is performed by the reaction represented by the following formula: 2Bi 2 Sr 2 Ca 1 Cu 2 Oy → Bi 2 Sr 2 Ca 2 Cu 3 Oy '+ Bi 2 Sr 2 CuOy " Can promote the conversion of the 80K-phase superconductor generated in the above into a 110K-phase superconductor, suppress the generation of Ca 2 PbO 4 , and reduce the influence of grain boundary precipitates of the sintered body.
出発組成を前述の範囲に限定した理由は、構成金属元
素のうち、Bi,Ca,Cuのいずれかでも前述した範囲より少
ないと80K相が多量に残り、また多いと不純物相が生成
し、超電導相が形成されない場合もある。Pbが0.1より
小さいと、焼結速度が遅くなるとともに110K相の生成が
少なくなり、また、0.6を越えるとCa2PbO4等の不純物が
生成し臨界温度（Tec）や臨界電流密度（Jc）を低下さ
せる。また、NaとLiが合量で0.01未満では系の焼結温度
が高くなり、それに伴いCa2PbO4の増加を招くとともに1
10K相の生成量を高めることができず、0.5を越えると粒
界に常伝導相が増加しTcを低下させるからである。The reason for limiting the starting composition to the above-mentioned range is that among the constituent metal elements, if any of Bi, Ca, and Cu is less than the above-mentioned range, a large amount of the 80K phase remains, and if it is too large, an impurity phase is generated and the superconducting phase is formed. In some cases, no phase is formed. If Pb is smaller than 0.1, the sintering speed is reduced and the generation of the 110K phase is reduced, and if it exceeds 0.6, impurities such as Ca 2 PbO 4 are generated and the critical temperature (Tec) and critical current density (Jc) Lower. On the other hand, if the total amount of Na and Li is less than 0.01, the sintering temperature of the system becomes high, which leads to an increase in Ca 2 PbO 4 and
This is because the amount of generation of the 10K phase cannot be increased, and if it exceeds 0.5, the normal conduction phase increases at the grain boundary and Tc decreases.
前述した出発組成の範囲の中でも、特にモル比におい
てSr＝２に対しBiを1.9乃至2.0、Pbを0.2乃至0.5、Caを
3.1乃至3.2、Cuを4.1乃至4.3およびNaとLiが合量で0.05
乃至0.20の範囲になるように調合するとより優れた110K
相の含有量の多い超電導体を得ることができる。Among the ranges of the starting composition described above, Bi is 1.9 to 2.0, Pb is 0.2 to 0.5, and Ca is
3.1 to 3.2, Cu to 4.1 to 4.3 and Na and Li in a total amount of 0.05
Better 110K when formulated to be in the range of ~ 0.20
A superconductor having a high phase content can be obtained.
本発明によれば、上記の成形体は、各金属の酸化物あ
るいは焼結によって酸化物に変換し得るものから成る
が、Na,Liにおいてはフッ化物、塩化物、シュウ化物、
ヨウ化物も適用される。例えば炭酸塩等の形態で調合し
た調合粉末、或いは調合粉末を例えば700〜845℃の温度
で仮焼し、その後仮焼粉末を所望の公知の成形方法で成
型したものであり、具体的にはプレス成型、ドクターブ
レード成型、押出成型、射出成型、圧延成型或いは銀パ
イプ中に入れ圧延する方法等が採用される。According to the present invention, the above-mentioned molded body is made of an oxide of each metal or a material that can be converted into an oxide by sintering, but in Na, Li, fluoride, chloride, oxalate,
Iodide also applies. For example, prepared powder prepared in the form of carbonates or the like, or prepared powder is calcined at a temperature of, for example, 700 to 845 ° C, and then the calcined powder is molded by a desired known molding method. Press molding, doctor blade molding, extrusion molding, injection molding, rolling molding, a method of rolling in a silver pipe, and the like are employed.
また、830℃以上で仮焼して、110K相を合成すると結
晶粒が大きくなり、成形時に配向させることができる。Further, when calcined at 830 ° C. or higher to synthesize a 110K phase, crystal grains become large and can be oriented at the time of molding.
次に、上記成形品を820乃至850℃、特に835〜845℃の
温度で且つ系に対し十分に酸素供給可能な酸化性雰囲
気、例えば大気中で焼成することにより、高110K相含有
の超電導体を得ることができる。Next, the molded article is fired in an oxidizing atmosphere at a temperature of 820 to 850 ° C., particularly 835 to 845 ° C. and in which oxygen can be sufficiently supplied to the system, for example, in the atmosphere to obtain a superconductor having a high 110K phase content. Can be obtained.
上記焼成条件において、焼成温度が820℃より低いと
超電導化合物が合成されず850℃より高いとCa2PbO4など
の不純物が生成する。Under the above firing conditions, if the firing temperature is lower than 820 ° C., a superconducting compound will not be synthesized, and if it is higher than 850 ° C., impurities such as Ca 2 PbO 4 will be generated.
また焼成時間は100時間以上であることが好ましく、1
00時間より短いと80K 相等の低Tc相が大部分を占め、11
0K相の単相化が達成されない傾向にある。Further, the firing time is preferably 100 hours or more, 1
If the time is shorter than 00 hours, low Tc phase such as 80K phase occupies most,
There is a tendency that the single phase of the 0K phase is not achieved.
なお、この焼成によれば、出発組成中Pbは、超電導相
に固溶し、Biサイトに置換するが、Na或いはLiは超電導
相に固溶することなく、粒界に存在するがほとんどが揮
散する傾向にある。このNa化合物或いはLi化合物は最終
焼結体中に存在すると超電導特性に対し悪影響を及ぼす
もので焼結中に積極的に揮散させることが必要である。According to this calcination, Pb in the starting composition dissolves in the superconducting phase and replaces the Bi site, but Na or Li do not dissolve in the superconducting phase and are present at the grain boundaries but almost volatilize. Tend to. If the Na compound or the Li compound is present in the final sintered body, it has an adverse effect on the superconducting properties, and must be volatilized actively during sintering.
よって、本発明によれば、最終的に得られる超電導体
の組成を、モル比率でSr＝２とした時、Biが1.8乃至2.
2、特に1.9乃至2.1、Pbが0.1乃至0.5、特に0.4乃至0.
5、Caが2.0乃至3.5、特に3.0乃至3.1、Cuが3.0乃至4.
5、特に4.0乃至4.2、NaとLiが合量で0.01以下、特に0.0
01乃至0.008の範囲になるように、Pb或いはNa,Liの揮散
量を焼成時間等により調整することにより、臨界温度Tc
eが100K以上の優れた超電導体が得られる。Therefore, according to the present invention, when the composition of the finally obtained superconductor is Sr = 2 in molar ratio, Bi is 1.8 to 2.
2, especially 1.9 to 2.1, Pb is 0.1 to 0.5, especially 0.4 to 0.
5, Ca is 2.0 to 3.5, especially 3.0 to 3.1, Cu is 3.0 to 4.
5, especially 4.0 to 4.2, the total amount of Na and Li is 0.01 or less, especially 0.0
By adjusting the volatilization amount of Pb or Na, Li by the firing time or the like so as to be in the range of 01 to 0.008, the critical temperature Tc
An excellent superconductor with an e of 100K or more can be obtained.
本発明における超電導体中の酸素量については定かで
はないが、焼結中、系自体が必要とする酸素を十分に供
給し得る雰囲気に保つことを除けば何ら制限するもので
はない。The amount of oxygen in the superconductor in the present invention is not known, but is not limited at all except that the sintering is carried out in an atmosphere capable of supplying sufficient oxygen required by the system itself.
このようにして得られる本発明の酸化物超電導体の特
徴としては、後述する実施例及び第１図乃至第３図から
明らかなように、80K相やCa2PbO4等の不純物相の生成が
少なく、100K以上の高い臨界温度（Tce）を有すること
の他に、第２図と第３図との比較からも明らかなよう
に、従来、８（Oe）の磁場中において4.2Kの液体ヘリウ
ム中でゼロ磁場に対し超電導相が約90％から約50％まで
減少するのに対し、本発明品は８（Oe）の磁場中でもほ
とんど変化しないという全く予想し得なかった優れた特
性を有するものである。このような現象の理由について
は定かではないが、粒界析出物の生成が抑制されること
によって粒界の弱結合部分（ウィークリンク）が解消さ
れ、磁場に対し影響を受け難い材料となるためと考えら
れる。As a feature of the oxide superconductor of the present invention obtained in this way, as is apparent from the examples described later and FIGS. 1 to 3, generation of an impurity phase such as an 80K phase or Ca 2 PbO 4. In addition to having a high critical temperature (Tce) of at least 100K, as is clear from the comparison between FIG. 2 and FIG. 3, the conventional liquid helium of 4.2K in a magnetic field of 8 (Oe) is conventionally used. The superconducting phase decreases from about 90% to about 50% with respect to zero magnetic field, whereas the product of the present invention has an unexpectedly excellent characteristic that it hardly changes even in a magnetic field of 8 (Oe). It is. The reason for such a phenomenon is not clear, but since the generation of grain boundary precipitates is suppressed, the weak link portion (weak link) of the grain boundary is eliminated, and the material becomes less susceptible to the magnetic field. it is conceivable that.
以下、本発明を次の例で説明する。 Hereinafter, the present invention will be described with reference to the following examples.
［実施例］ 原料粉末としてBi2O3,PbO,SrCO3,CaCO3,CuO の各粉末
を用いて各金属のモル比が第１表になるように、秤量
後、750〜810 ℃で20時間仮焼後、粉砕し平均粒径５μ
ｍの仮焼粉末を得た。この仮焼粉末に対し、Na2CO3,Li2
CO3を第１表のモル比になるよう秤量添加して乳鉢で混
合後、φ12の金型を用いて成形圧1t/cm2で厚み約1mmの
円板状試料を作製した。[Example] Bi 2 O 3 , PbO, SrCO 3 , CaCO 3 , and CuO powders were used as raw material powders, weighed so that the molar ratio of each metal was as shown in Table 1, and weighed at 750 to 810 ° C. After calcining for hours, pulverize and average particle size 5μ
m was obtained. Na 2 CO 3 , Li 2
CO 3 was weighed and added to the molar ratio shown in Table 1 and mixed in a mortar. Then, a disc-shaped sample having a molding pressure of 1 t / cm 2 and a thickness of about 1 mm was prepared using a φ12 mold.
この試料を第１表の条件にて焼成した。 This sample was fired under the conditions shown in Table 1.
得られた焼結体に対し、比重をアルキメデス法によ
り、臨界温度（Tce）を電気抵抗変化から求め、更に交
流帯磁率測定から、90Kにおける超電導体の比率を求め
た。For the obtained sintered body, the specific gravity was determined by the Archimedes method from the change in electrical resistance, and the ratio of the superconductor at 90 K was determined from the AC susceptibility measurement.
結果は第１表に示した。 The results are shown in Table 1.
表中、Naを添加したNo.2と、全くNa或いはLiを添加し
なかったNo.1の試料のＸ線回折チャートを第１図に示し
た。第１図によれば、従来品No.1は80K相及びCa2PbO4の
ピークが観察されるのに対し、本発明品No.2は80K相の
ピーク及びCa2PbO4の相が小さくなっていることが理解
される。 FIG. 1 shows the X-ray diffraction charts of No. 2 to which Na was added and No. 1 to which no Na or Li was added. According to FIG. 1, the conventional product No. 1 has a peak of 80 K phase and Ca 2 PbO 4 , whereas the present product No. 2 has a small peak of 80 K phase and a small phase of Ca 2 PbO 4. It is understood that it is.
次に、第１図で用いた同じ試料に対し、温度−抵抗及
び温度−帯磁率との関係をそれぞれ第２図に本発明品N
o.2、第３図に従来品No.1を図示した。Next, for the same sample used in FIG. 1, the relationship between temperature-resistance and temperature-susceptibility is shown in FIG.
o.2 and Fig. 3 show the No.1 conventional product.
第２図と第３図との比較によれば、従来品である第３
図では温度−抵抗曲線において110K付近にオンセット温
度（Tco）が存在するものの、中間付近にて段差が生じ
オフセット温度（Tce）は89Kであった。これは、110K相
を含むものの、80K相等の異相が生じていることを意味
するものである。また、温度−帯磁率曲線において4.2K
の液体ヘリウム中で0.8（Oe）では約88％と高いもの
の、８（Oe）では約52％とその帯磁率が大きく変化する
ことがわかる。According to a comparison between FIG. 2 and FIG.
In the figure, although the onset temperature (Tco) exists near 110 K in the temperature-resistance curve, a step occurs near the middle, and the offset temperature (Tce) is 89 K. This means that a different phase, such as the 80K phase, has occurred, although it contains the 110K phase. In addition, 4.2K in the temperature-susceptibility curve
It can be seen that the magnetic susceptibility of the liquid helium of 0.8 (Oe) is as high as about 88%, but that of 8 (Oe) is as large as about 52%.
それに対し、第２図の本発明品では温度−抵抗曲線に
おいて200K付近における抵抗値は約4mΩと小さく、120K
付近にオンセット温度（Tco）を有し、第３図のように
段差を生じることなく、単調に減少し、オフセット温度
（Tce）は107Kと高い値を示し、80Kの異相がほとんど生
じていないことがわかる。また温度−帯磁率曲線におい
て4.2Kにて約98％の高い帯磁率を示し、８（Oe）の磁場
中においてもほとんど曲線に変化がなく、磁場に対し強
いことが理解される。On the other hand, in the product of the present invention shown in FIG. 2, the resistance value at around 200 K in the temperature-resistance curve is as small as about 4 mΩ,
It has an onset temperature (Tco) in the vicinity, decreases monotonously without generating a step as shown in FIG. 3, shows a high offset temperature (Tce) of 107 K, and hardly generates a different phase of 80 K. You can see that. Further, the temperature-susceptibility curve shows a high susceptibility of about 98% at 4.2 K, and it is understood that there is almost no change in the curve even in the magnetic field of 8 (Oe), and it is strong against the magnetic field.
一方、第１表によれば、NaおよびLiの添加合量がSr＝
２に対し0.5を越える試料No.4,10,13はいずれも最終焼
結体中の残存量が多く、高い臨界温度は示さなかった。
また、Bi量が少なすぎる試料No.5ではほとんど超電導体
が生成されなかった。また、Pbの量が少ないと臨界温度
が低く、超電導相の生成割合も低いものであった。On the other hand, according to Table 1, the added amount of Na and Li is Sr =
Sample Nos. 4, 10, and 13 exceeding 0.5 with respect to 2 each had a large amount of residual in the final sintered body and did not show a high critical temperature.
Further, in Sample No. 5 in which the Bi content was too small, almost no superconductor was generated. Also, when the amount of Pb was small, the critical temperature was low, and the generation rate of the superconducting phase was low.
これに対し、本発明の試料はいずれも臨界温度100Kを
越えるものであり且つ超電導相の生成比率も80％以上で
あった。In contrast, all of the samples of the present invention exceeded the critical temperature of 100 K, and the formation ratio of the superconducting phase was 80% or more.
［発明の効果］ 以上、詳述した通り、本発明によれば、Bi−Pb−Sr−
Ca−Cu−Ｏ系超電導体にNaあるいはLiを適量添加するこ
とによって、80K相や他の不純物の析出を抑制し、110K
相を多量に含むことによって高い臨界温度（Tc）が付与
でき、しかも磁場変化に対し、特性に変化の少ない優れ
た超電導体を得ることができ、磁気シールド材をはじめ
各種電子部品等への適用を促進することができる。[Effects of the Invention] As described above in detail, according to the present invention, Bi-Pb-Sr-
By adding an appropriate amount of Na or Li to the Ca-Cu-O-based superconductor, the precipitation of the 80K phase and other impurities is suppressed,
A high critical temperature (Tc) can be imparted by containing a large amount of phases, and an excellent superconductor with little change in characteristics with respect to magnetic field changes can be obtained. Application to various electronic components such as magnetic shield materials Can be promoted.
第１図は本発明品No.2及び従来品No.1におけるＸ線回折
チャート図、第２図及び第３図はいずれも温度−抵抗及
び温度−帯磁率との関係を示す図で第２図が本発明品N
o.2、第３図が従来品No.1のものを示す。FIG. 1 is an X-ray diffraction chart of the product No. 2 of the present invention and the conventional product No. 1, and FIGS. 2 and 3 are diagrams showing the relationship between temperature-resistance and temperature-susceptibility. The figure shows the product N of the present invention.
o.2 and Fig.3 show the conventional product No.1.
フロントページの続き 審査官 米田 健志 (58)調査した分野(Int.Cl.6，ＤＢ名) C04B 35/00 - 35/22 C04B 35/447 - 35/457 C01G 1/00 - 57/00Continuing from the front page Examiner Kenshi Yoneda (58) Field surveyed (Int. Cl. 6 , DB name) C04B 35/00-35/22 C04B 35/447-35/457 C01G 1/00-57/00
Claims (2)
の少なくともいずれか、および酸素とから成り、各金属
元素のモル比率がSrのモル数を２とした時、Biが1.8乃
至2.2、Pbが0.1乃至0.5、Caが2.0乃至3.5、Cuが3.0乃至
4.5、Na,Liの少なくともいずれかが合量で0.01以下（但
し、０を含まず）の組成から成る臨界温度（Tce）が100
K以上の酸化物超電導体。(1) Bi, Pb, Sr, Ca, Cu and Na, Li as metal elements
At least any one of and oxygen, and when the molar ratio of each metal element is 2 moles of Sr, Bi is 1.8 to 2.2, Pb is 0.1 to 0.5, Ca is 2.0 to 3.5, and Cu is 3.0 to 3.5.
4.5 Critical temperature (Tce) consisting of a composition in which at least one of Na and Li is 0.01 or less in total (but not including 0) is 100
Oxide superconductor of K or more.
の少なくともいずれかの酸化物から成り、各金属のモル
比率においてSrのモル数を２とした時、Biが1.8乃至2.
2、Pbが0.1乃至0.5、Caが2.0乃至3.5、Cuが3.0乃至4.
5、Na,Liの少なくともいずれかが合量で0.01乃至0.5の
割合から成る成形体を820乃至850℃の酸素含有雰囲気で
焼成する酸化物超電導体の製造方法。2. Bi, Pb, Sr, Ca, Cu and Na, Li as constituent elements
When the number of moles of Sr is 2 in the molar ratio of each metal, Bi is 1.8 to 2.
2, Pb is 0.1 to 0.5, Ca is 2.0 to 3.5, Cu is 3.0 to 4.
5. A method for producing an oxide superconductor, in which a compact comprising at least one of Na and Li in a total amount of 0.01 to 0.5 is fired in an oxygen-containing atmosphere at 820 to 850 ° C.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1308618A JP2789118B2 (en) | 1989-11-27 | 1989-11-27 | Oxide superconductor and manufacturing method thereof |
| US07/600,194 US5108985A (en) | 1989-11-27 | 1990-10-17 | Bi-Pb-Sr-Ca-Cu oxide superconductor containing alkali metal and process for preparation thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1308618A JP2789118B2 (en) | 1989-11-27 | 1989-11-27 | Oxide superconductor and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03170335A JPH03170335A (en) | 1991-07-23 |
| JP2789118B2 true JP2789118B2 (en) | 1998-08-20 |
Family
ID=17983217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1308618A Expired - Lifetime JP2789118B2 (en) | 1989-11-27 | 1989-11-27 | Oxide superconductor and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2789118B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5324712A (en) * | 1991-08-16 | 1994-06-28 | Gte Laboratories Incorporated | Formation of the high TC 2223 phase in BI-SR-CA-CU-O by seeding |
-
1989
- 1989-11-27 JP JP1308618A patent/JP2789118B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03170335A (en) | 1991-07-23 |
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