JP2642194B2 - Oxide superconducting material and its manufacturing method - Google Patents
Oxide superconducting material and its manufacturing methodInfo
- Publication number
- JP2642194B2 JP2642194B2 JP1168921A JP16892189A JP2642194B2 JP 2642194 B2 JP2642194 B2 JP 2642194B2 JP 1168921 A JP1168921 A JP 1168921A JP 16892189 A JP16892189 A JP 16892189A JP 2642194 B2 JP2642194 B2 JP 2642194B2
- Authority
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- Japan
- Prior art keywords
- superconducting material
- temperature
- sample
- oxygen
- heat treatment
- 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
Links
- 239000000463 material Substances 0.000 title claims description 30
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 32
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 30
- 239000001301 oxygen Substances 0.000 claims description 30
- 238000010438 heat treatment Methods 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 10
- 229910052693 Europium Inorganic materials 0.000 claims description 7
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 7
- 229910052779 Neodymium Inorganic materials 0.000 claims description 6
- 229910052772 Samarium Inorganic materials 0.000 claims description 6
- 229910052684 Cerium Inorganic materials 0.000 claims description 5
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 4
- 229910052788 barium Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 238000005245 sintering Methods 0.000 claims description 3
- -1 or Dy) Inorganic materials 0.000 claims 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 229910052761 rare earth metal Inorganic materials 0.000 description 7
- 238000000634 powder X-ray diffraction Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000007704 transition Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000002411 thermogravimetry Methods 0.000 description 2
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 1
- 238000003991 Rietveld refinement Methods 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 229910009203 Y-Ba-Cu-O Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical group [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002887 superconductor Substances 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)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、比較的高い臨界温度を有し、比較的安価な
酸化物超電導材料とその製造方法に関する。Description: TECHNICAL FIELD The present invention relates to a relatively inexpensive oxide superconducting material having a relatively high critical temperature and a method for producing the same.
従来の技術 1980年に30K以上の高い臨界温度を有するLa−Ba−Cu
−Ｏ系の超電導酸化物（（LaBa）2CuO4）が発見されて
以来、酸化物超電導材料が注目を集めている。1987年に
は、Ｙ−Ba−Cu−Ｏ系の超電導酸化物（LaBa2Cu3Oyの臨
界温度が液体窒素温度（77K）よりも高い約90Kであるこ
とが確認された。また1988年には、Bi−Sr−Ca−Cu−Ｏ
系、およびTl−Ba−Ca−Cu−Ｏ系超電導材料が発見さ
れ、臨界温度は100K以上になった（北沢宏一・岸尾光
二、「応用物理」、57巻、pp1644−1665、1988年）。Prior art La-Ba-Cu having a high critical temperature of 30K or more in 1980
-O-based superconducting oxides ((LaBa) 2 CuO 4) Since the discovery of oxide superconducting materials have been attracting attention. In 1987, it was confirmed that the critical temperature of the Y-Ba-Cu-O-based superconducting oxide (LaBa 2 Cu 3 O y ) was about 90 K, which is higher than the liquid nitrogen temperature (77 K). Bi-Sr-Ca-Cu-O
System and Tl-Ba-Ca-Cu-O-based superconducting material were discovered, and the critical temperature became 100K or more (Koichi Kitazawa and Koji Kishio, "Applied Physics", Vol. 57, pp. 1644-1665, 1988).
発明が解決しようとする課題 しかしながら、超電導材料を各種センサやデバイスな
どに応用する際には、それぞれの用途に見合った、適当
な臨界温度を有する比較的安価な超電導材料が必要であ
る。However, when a superconducting material is applied to various sensors and devices, a relatively inexpensive superconducting material having an appropriate critical temperature suitable for each application is required.
本発明は、このような課題を解決するためになされた
もので、約40Kの臨界温度を実現することが可能で比較
的安価な超電導材料を提供することを目的とする。The present invention has been made to solve such a problem, and an object of the present invention is to provide a relatively inexpensive superconducting material capable of realizing a critical temperature of about 40K.
課題を解決するための手段 本発明は上記目的を達成するため、少なくとも、La、
Ln（Nd、Sm、Eu、Gd、Dy）、Ba、Ce、Cu、Ｏの元素から
構成され、組成式がLapLnqBarCesCu9O30-zで表され、
ｐ、ｑ、ｒ、ｓが次の条件 ｐ＋ｑ＋ｒ＋ｓ＝12 ０＜ｐ＜5.5 0.5＜ｑ＜7.5 1.5＜ｒ＜5.5 0.5＜ｓ＜3.5 を満たすものであることを特徴とする。Means for Solving the Problems The present invention has at least La,
Ln (Nd, Sm, Eu, Gd, Dy), Ba, Ce, Cu, is composed of elements of O, represented by a compositional formula of La p Ln q Ba r Ce s Cu 9 O 30-z,
It is characterized in that p, q, r, and s satisfy the following condition: p + q + r + s = 120 <p <5.50.5 <q <7.51.5 <r <5.50.5 <s <3.5.
本発明の酸化物超電導材料の製造方法は、酸素雰囲気
で上記組成物の加熱処理を行って焼結した後、酸素雰囲
気中で熱処理（300〜700℃）を行って酸素を吸収させる
ことを特徴とする。The method for producing an oxide superconducting material according to the present invention is characterized in that the composition is subjected to a heat treatment in an oxygen atmosphere, sintered, and then subjected to a heat treatment (300 to 700 ° C.) in an oxygen atmosphere to absorb oxygen. And
作用 上記構成によれば、結晶構造が従来の（LaBa）2CuO4
系超電導材料やLaBa2Cu3Oy系超電導材料と全く異なる新
規な酸化物超電導材料を得ることができる。しかも焼結
に要する加熱処理時間が従来例に比べて短くて済み製造
が容易なので、製造コストを抑えることができる。Action According to the above configuration, the crystal structure is the same as that of the conventional (LaBa) 2 CuO 4
It is possible to obtain a novel oxide superconducting material which is completely different from the superconducting material based on La-based or LaBa 2 Cu 3 O y based material. In addition, since the heat treatment time required for sintering is shorter than that of the conventional example and the production is easy, the production cost can be suppressed.
また上記組成式において、ｐ、ｑ、ｒ、ｓを、1.5＜
ｐ＜3.5、2.5＜ｑ＜4.5、ｒ＝４、ｓ＝２とすることに
より、15K以上の臨界温度を実現することが可能であ
る。更に、加熱処理時の酸素分圧を0.1気圧以下に設定
したり、熱処理時の酸素分圧を１気圧以上に設定するこ
とにより、臨界温度40Kを実現することが可能である。In the above composition formula, p, q, r, and s are set to 1.5 <
By setting p <3.5, 2.5 <q <4.5, r = 4, and s = 2, it is possible to realize a critical temperature of 15K or more. Further, by setting the oxygen partial pressure during the heat treatment to 0.1 atm or less, or setting the oxygen partial pressure during the heat treatment to 1 atm or more, it is possible to achieve a critical temperature of 40K.
この結果、各種センサやデバイスなどに応用する際、
それぞれの用途に見合った適当な臨界温度を有する超電
導材料を比較的安価に提供することができる。As a result, when applied to various sensors and devices,
A superconducting material having an appropriate critical temperature suitable for each application can be provided relatively inexpensively.
実 施 例 本発明の第１の実施例における酸化物超電導材料とそ
の製造方法を説明する。EXAMPLE An oxide superconducting material according to a first example of the present invention and a method for manufacturing the same will be described.
出発原料として、市販の試薬を用いて第１表に示した
組成の試料No.1〜22を作製した。Sample Nos. 1 to 22 having the compositions shown in Table 1 were prepared using commercially available reagents as starting materials.
試料の製造方法を試料No.4の製造方法を例に説明す
る。出発原料として市販のLa2O3、Gd2O3、BaCO3、Ce
O2、CuOを用いた。これらの原料を十分に乾燥させたの
ち、本発明の組成式LapLnqBarCesCu9O30-zに基づいて、
La3Gd3Ba4Ce2Cu9O30-zの化学式となるように配合した。
この混合粉を直径40mm、厚さ5mmの円柱形にプレス成形
し、酸素雰囲気中1020℃で20時間仮焼した。得られた仮
焼粉を十分に粉砕し、2mm×2mm×20mmの直方体にプレス
成形 した。次いで、この成形体を炉内で酸素ガスを流通させ
ながら1030℃で20時間加熱処理を行って焼結した後、50
℃/minで冷却した。冷却時、600℃で20時間、400℃で20
時間熱処理を行い、酸素を十分に吸収させた。熱処理
後、そのまま常温まで放冷した。The method of manufacturing the sample will be described by taking the manufacturing method of sample No. 4 as an example. Commercially available starting materials La 2 O 3 , Gd 2 O 3 , BaCO 3 , Ce
O 2 and CuO were used. After these raw materials were sufficiently dried, on the basis of the composition formula La p Ln q Ba r Ce s Cu 9 O 30-z of the present invention,
La 3 Gd 3 Ba 4 Ce 2 Cu 9 O was blended so as to have a chemical formula of 30-z .
This mixed powder was press-molded into a cylinder having a diameter of 40 mm and a thickness of 5 mm, and calcined at 1020 ° C. for 20 hours in an oxygen atmosphere. The obtained calcined powder is sufficiently pulverized and pressed into a 2 mm x 2 mm x 20 mm rectangular parallelepiped did. Next, after sintering the molded body at 1030 ° C. for 20 hours while flowing oxygen gas in a furnace,
Cooled at ° C / min. Cooling, 20 hours at 600 ° C, 20 hours at 400 ° C
Heat treatment was performed for a long time to sufficiently absorb oxygen. After the heat treatment, it was allowed to cool to room temperature.
炉から取出した試料No.4の抵抗−温度特性を通常の４
端子法で測定した。その結果を第１図に示した。この試
料No.4の超電導の開始温度（オンセット温度）は32Kで
あり、抵抗率ゼロとなる温度は27Kであった。この試料N
o.4の交流帯磁率を測定したところ、測定値は32K以下で
負の値となり、マイスナー効果が認められた。The resistance-temperature characteristics of sample No. 4 taken out of the furnace
It was measured by the terminal method. The results are shown in FIG. The superconducting start temperature (onset temperature) of this sample No. 4 was 32K, and the temperature at which the resistivity became zero was 27K. This sample N
When the AC susceptibility of o.4 was measured, the measured value became a negative value below 32K, and the Meissner effect was recognized.
この試料No.4の結晶構造を粉末Ｘ線回折によって調べ
た。Ｘ線源にはCuKγ線を用いた。得られた粉末Ｘ線回
折図形を第２図に示した。この粉末Ｘ線回折図形は、す
でに超電導体として知られている（LaBa）2CuO4やLaBa2
Cu3Oyの粉末Ｘ線回折図形と全く異なっていた。粉末Ｘ
線回折から得られたピークは、ａ＝3.83Å、ｃ＝28.30
Åの格子定数をもつ正方晶系の単位格子を仮定すると、
すべて指数付することができた。第２図の粉末Ｘ線図形
の各ピークにそれぞれの指数を与えた。The crystal structure of this sample No. 4 was examined by powder X-ray diffraction. CuKγ rays were used as the X-ray source. The resulting powder X-ray diffraction pattern is shown in FIG. This powder X-ray diffraction pattern shows that (LaBa) 2 CuO 4 and LaBa 2
It was completely different from the powder X-ray diffraction pattern of Cu 3 O y . Powder X
The peaks obtained from the line diffraction were a = 3.83 ° and c = 28.30.
Assuming a tetragonal unit cell with a lattice constant of Å,
All could be indexed. Each peak of the powder X-ray pattern in FIG. 2 was given an index.
この従来にない新規な超電導化合物の結晶構造を明ら
かにするために粉末Ｘ線回折図形のリートベルト解析を
行った。こうして得られた結晶構造の概略図を第３図に
示した。この化合物の結晶構造は、従来から超電導体と
して知られている（LaBa）2CuO4やLaBa2Cu3Oyの結晶構
造と全く異なっていた。To clarify the crystal structure of this novel superconducting compound, Rietveld analysis of powder X-ray diffraction pattern was performed. FIG. 3 shows a schematic diagram of the crystal structure thus obtained. The crystal structure of this compound was completely different from the crystal structure of (LaBa) 2 CuO 4 or LaBa 2 Cu 3 O y conventionally known as a superconductor.
この試料No.4の酸素含有量（30−ｚ）を不活性ガス融
解−非分散赤外線吸収法によって分析した。得られた値
は、酸素含有量が約27.4であった。したがって、酸素欠
損量（ｚ）は2.6となる。The oxygen content (30-z) of this sample No. 4 was analyzed by an inert gas melting-non-dispersive infrared absorption method. The value obtained was about 27.4 oxygen content. Therefore, the oxygen deficiency (z) is 2.6.
また、この試料No.4の酸素の吸収・放出特性を調べる
ために熱重量（TG）分析を行った。測定の際、酸素雰囲
気中で室温から1000℃の間で加熱及び冷却を行った。試
料No.4の重量は約100mgであり、加熱及び冷却速度は10
℃/minである。得られたTG曲線を第４図に示した。この
結果からこの試料No.4は、300℃以上の温度で可逆的に
酸素を吸収及び放出することがわかる。それで、800
℃、700℃、600℃と熱処理温度を変化させて、その後、
室温まで急冷して試料を作製したところ熱処理温度が80
0℃の場合には超電導転移を示さなかった。したがっ
て、熱処理温度としては、酸素を吸収する最低温度であ
る300℃以上であり、酸素を十分に吸収する最高温度で
ある700℃以下が適当であることがわかる。なお、この
熱重量分析は酸素１気圧下の測定であるので、酸素分圧
が１気圧以上になると試料中に酸素がより吸収されやす
くなるから熱処理に望ましい温度範囲が１気圧の場合の
300〜700℃の範囲より広がるのは当然である。In addition, thermogravimetric (TG) analysis was performed to examine the oxygen absorption / desorption characteristics of Sample No. 4. During the measurement, heating and cooling were performed at room temperature to 1000 ° C. in an oxygen atmosphere. Sample No. 4 weighs about 100 mg and has a heating and cooling rate of 10
° C / min. The obtained TG curve is shown in FIG. From this result, it is understood that this sample No. 4 reversibly absorbs and releases oxygen at a temperature of 300 ° C. or more. So 800
℃, 700 ℃, change the heat treatment temperature to 600 ℃, then
The sample was quenched to room temperature and the heat treatment temperature was 80
No superconducting transition was shown at 0 ° C. Therefore, it is understood that the heat treatment temperature is 300 ° C. or more, which is the lowest temperature for absorbing oxygen, and 700 ° C. or less, which is the highest temperature for sufficiently absorbing oxygen. Since the thermogravimetric analysis is a measurement under 1 atm of oxygen, when the oxygen partial pressure is 1 atm or more, oxygen is more easily absorbed in the sample, so that the preferable temperature range for the heat treatment is 1 atm.
Naturally, it spreads out from the range of 300 to 700 ° C.
試料No.1〜５は、La、Ce以外の希土類元素LnをNd、S
m、Eu、Gd、Dyと変化させた試料である。試料No.6〜11
は、Laと他の希土類元素Ln（本実施冷の場合、Gd）との
比率を変化させたものである。試料No.12〜18は、Baと
希土類元素Ln（本実施例の場合、Nd）またはLaとの比率
を変化させた試料であり、試料No.19〜22はCeと他の希
土類元素Ln（本実施例の場合、Gd）との比率を変化させ
たものである。Sample Nos. 1 to 5 were obtained by converting rare earth elements Ln other than La and Ce into Nd, S
The sample was changed to m, Eu, Gd, and Dy. Sample No. 6 ~ 11
Is obtained by changing the ratio of La to another rare earth element Ln (Gd in the case of the present cooling). Samples Nos. 12 to 18 are samples in which the ratio of Ba to rare earth element Ln (in the case of this embodiment, Nd) or La was changed, and samples Nos. 19 to 22 were Ce and other rare earth elements Ln ( In the case of the present embodiment, the ratio with Gd) is changed.
第１表に示した組成の試料No.1〜22の超電導特性を第
２表に示した。この表でオンセット温度とは第１図に示
したように、試料の超電導転移の開始温度であり、試料
を冷却していった際に電気抵抗率が低下し始める温度で
ある。ゼロ抵抗温度とは、超電導状態になったために試
料の電気抵抗がゼロになった温度である。第２表で−印
は、超電導転移のオンセットあるいは、ゼロ抵抗が観測
されなかったことを示している。Table 2 shows the superconducting characteristics of Sample Nos. 1 to 22 having the compositions shown in Table 1. In this table, the onset temperature is, as shown in FIG. 1, the temperature at which the superconducting transition of the sample starts, and the temperature at which the electrical resistivity starts to decrease when the sample is cooled. The zero resistance temperature is a temperature at which the electrical resistance of the sample becomes zero due to the superconducting state. In Table 2, the symbol-indicates that no onset of the superconducting transition or zero resistance was observed.
試料No.1〜５を比較すると、希土類元素LnとしてNd、
Sm、Eu、Gd、Dyのいずれを用いても超電導転移を示すこ
とがわかる。また、試料No.6〜11を比較するとLaの望ま
しい組成範囲としては、０＜ｐ＜5.5であることがわか
る。試料No.6〜14を比較すると、超電導になるのは、 La、Ce以外の希土類元素Lnの組成範囲が、0.5＜ｑ＜7.5
であることがわかる。試料No.14〜18を見るとBaの望ま
しい組成比率としては、1.5＜ｒ＜5.5の範囲であり、ま
た試料No.19〜22を比較すると、Ceの組成比率として
は、0.5＜ｓ＜3.5の範囲が望ましいことがわかる。Comparing Sample Nos. 1 to 5, Nd and Rd as rare earth elements Ln
It can be seen that any of Sm, Eu, Gd, and Dy shows a superconducting transition. Comparing Samples Nos. 6 to 11, it can be seen that the desirable composition range of La is 0 <p <5.5. When comparing sample Nos. 6 to 14, the superconductivity is The composition range of the rare earth element Ln other than La and Ce is 0.5 <q <7.5.
It can be seen that it is. Looking at Sample Nos. 14 to 18, the desirable composition ratio of Ba is in the range of 1.5 <r <5.5, and comparing Sample Nos. 19 to 22, the composition ratio of Ce is 0.5 <s <3.5. It can be seen that the range is desirable.
また、第１表および第２表をながめてみると、特に希
土類元素LnがNd、Sm、Eu、Gdのいずれかであり、ｐ、
ｑ、ｒ、ｓが 1.5＜ｐ＜3.5 2.5＜ｑ＜4.5 ｒ＝４ ｓ＝２ の範囲にある試料No.1〜４、８では、いずれも15K以上
でゼロ抵抗になりきわめて良好な超電導特性を示すこと
がわかる。Looking at Tables 1 and 2, particularly, the rare earth element Ln is one of Nd, Sm, Eu, and Gd, and p,
Samples Nos. 1 to 4 and 8 in which q, r, and s are in the range of 1.5 <p <3.5 2.5 <q <4.5 r = 4 s = 2 have zero resistance at 15 K or more, and have very good superconducting characteristics. It can be seen that
なお、本実施例に示すように本発明の酸化物超電導材
料は比較的純粋であるので、臨界電流を大きくすること
が可能である。Note that, as shown in this example, the oxide superconducting material of the present invention is relatively pure, so that the critical current can be increased.
本発明の第２の実施例における酸化物超電導材料とそ
の製造方法を説明する。A description will be given of an oxide superconducting material and a method of manufacturing the same according to a second embodiment of the present invention.
第１の実施例で作成した試料No.4を酸素分圧２気圧
（試料No.23）、10気圧（試料No.24）、50気圧（試料N
o.25）、200気圧（試料No.26）の高酸素圧の条件で600
℃と400℃でそれぞれ20時間づつ熱処理を行って酸素を
吸収させ、４種の試料No.23〜26を得た。これらの試料N
o.23〜26の抵抗−温度特性を第５図に示した。また、オ
ンセット温度とゼロ抵抗温度を第３表に示した。Sample No. 4 prepared in the first embodiment was subjected to oxygen partial pressure of 2 atm (sample No. 23), 10 atm (sample No. 24), and 50 atm (sample N).
o.25) and 600 at high pressure of 200 atm (sample No.26).
Heat treatment was performed at 20 ° C. and 400 ° C. for 20 hours each to absorb oxygen, and four types of samples Nos. 23 to 26 were obtained. These samples N
The resistance-temperature characteristics of o.23 to 26 are shown in FIG. Table 3 shows the onset temperature and the zero resistance temperature.
この結果、熱処理の時の酸素分圧が高いほど、試料の
抵抗率の値が小さくなり、超電導転移の温度も高くなる
ことがわかる。 As a result, it is found that the higher the oxygen partial pressure during the heat treatment, the lower the resistivity of the sample and the higher the superconducting transition temperature.
本発明の第３の実施例における酸化物超電導材料とそ
の製造方法を説明する。A description will be given of an oxide superconducting material and a method of manufacturing the same according to a third embodiment of the present invention.
第１の実施例の試料No.4と同じ仮焼粉を十分に粉砕
し、2mm×2mm×20mmの直方体にプレス成形した。次い
で、この成形体を炉内で、本実施例では窒素ガスを流通
させながら900℃で20時間加熱処理を行って焼結した。
その後、ガスを窒素から酸素に切替えて50℃/minで冷却
した。冷却時、600℃で20時間、400℃で20時間熱処理を
行い、酸素を十分に吸収させた。熱処理後、そのまま常
温まで放冷した。The same calcined powder as the sample No. 4 of the first embodiment was sufficiently pulverized and press-formed into a rectangular parallelepiped of 2 mm × 2 mm × 20 mm. Next, this molded body was subjected to a heat treatment at 900 ° C. for 20 hours in a furnace while flowing nitrogen gas in the present embodiment, and was sintered.
Thereafter, the gas was switched from nitrogen to oxygen and cooled at 50 ° C./min. During cooling, heat treatment was performed at 600 ° C. for 20 hours and at 400 ° C. for 20 hours to sufficiently absorb oxygen. After the heat treatment, it was allowed to cool to room temperature.
炉から取出した試料の抵抗−温度特性を通常の４端子
法で測定した。この試料の超電導の開始温度は35Kであ
り、抵抗率ゼロとなる温度は30Kであった。これらの値
は、酸素雰囲気で加熱処理した試料No.4よりも高い値で
あった。The resistance-temperature characteristics of the sample taken out of the furnace were measured by a normal four-terminal method. The starting temperature of superconductivity of this sample was 35K, and the temperature at which the resistivity became zero was 30K. These values were higher than that of Sample No. 4 which was heat-treated in an oxygen atmosphere.
また、加熱処理の雰囲気を、窒素ガス雰囲気から窒素
ガスと酸素ガスを混合した酸素分圧0.1気圧の雰囲気で
行っても試料No.4もりも臨界温度が高くなった（開始温
度:33K、ゼロ抵抗温度:28K）。In addition, even when the atmosphere of the heat treatment was performed from a nitrogen gas atmosphere to an atmosphere having a partial pressure of oxygen of 0.1 atm in which nitrogen gas and oxygen gas were mixed, the critical temperature of sample No. 4 became higher (start temperature: 33 K, zero Resistance temperature: 28K).
発明の効果 本発明は、従来の（LaBa）2CuO4系超電導材料やLaBa2
Cu3Oy系超電導材料と全く異なる新規な結晶構造を有
し、臨界温度40Kを実現することが可能な酸化物超電導
材料を低コストで製造することができるので、各種セン
サやデバイスなどに応用する際、それぞれの用途に見合
った適当な臨界温度を有する超電導材料を比較的安価に
提供することができる。Advantageous Effects of the Invention The present invention relates to conventional (LaBa) 2 CuO 4 -based superconducting materials and LaBa 2
An oxide superconducting material that has a novel crystal structure completely different from Cu 3 Oy- based superconducting materials and can achieve a critical temperature of 40K can be manufactured at low cost, so it is applied to various sensors and devices. In this case, a superconducting material having an appropriate critical temperature suitable for each application can be provided relatively inexpensively.
第１図は本発明の第１の実施例における酸化物超電導材
料の抵抗−温度特性図、第２図は同材料の粉末Ｘ線回折
図、第３図は同材料結晶構造の概略図、第４図は同材料
の熱重量分析（TG）曲線図、第５図は本発明の第２の実
施例における酸化物超電導材料の抵抗−温度特性図であ
る。FIG. 1 is a resistance-temperature characteristic diagram of the oxide superconducting material in the first embodiment of the present invention, FIG. 2 is a powder X-ray diffraction diagram of the same material, FIG. FIG. 4 is a thermogravimetric analysis (TG) curve diagram of the same material, and FIG. 5 is a resistance-temperature characteristic diagram of the oxide superconducting material in the second embodiment of the present invention.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 和田 隆博 東京都江東区東雲１丁目10番13号 財団 法人国際超電導産業技術研究センター超 電導工学研究所内 (72)発明者 一瀬 中 東京都江東区東雲１丁目10番13号 財団 法人国際超電導産業技術研究センター超 電導工学研究所内 (72)発明者 八重樫 裕司 東京都江東区東雲１丁目10番13号 財団 法人国際超電導産業技術研究センター超 電導工学研究所内 (72)発明者 山内 尚雄 東京都江東区東雲１丁目10番13号 財団 法人国際超電導産業技術研究センター超 電導工学研究所内 (72)発明者 田中 昭二 東京都江東区東雲１丁目10番13号 財団 法人国際超電導産業技術研究センター超 電導工学研究所内 (56)参考文献 特開 平３−33055（ＪＰ，Ａ) ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Wada 1-10-13 Shinonome, Koto-ku, Tokyo Within the Superconductivity Engineering Laboratory, International Superconducting Technology Research Center (72) Inventor Naka Ichinose Shinonome, Koto-ku, Tokyo 1-10-13 Inside the Superconductivity Engineering Research Center, International Superconducting Technology Research Center (72) Inventor Yuji Yaegashi 1-10-13 Shinonome, Shintomo, Koto-ku, Tokyo Inside the Superconducting Engineering Research Institute, International Superconducting Technology Research Center (72) Inventor Naoo Yamauchi 1-10-13 Shinonome, Koto-ku, Tokyo Inside the Superconductivity Research Laboratory, International Superconducting Technology Research Center (72) Inventor Shoji Tanaka 1-1-10-13, Shinonome, Koto-ku, Tokyo Foundation International Superconducting Technology Research Center, Superconductivity Engineering Laboratory (56) Japanese Patent Application Laid-Open No. 3-33055 (JP, A)
Claims (5)
たはDyから選ばれた少なくとも一種）、Ba、Ce、Cu、Ｏ
の元素から構成され、組成式がLapLnqBarCesCu9O30-zで
表され、ｐ、ｑ、ｒ、ｓが次の条件 ｐ＋ｑ＋ｒ＋ｓ＝12 ０＜ｐ＜5.5 0.5＜ｑ＜7.5 1.5＜ｒ＜5.5 0.5＜ｓ＜3.5 を満たすものである酸化物超電導材料。1. At least La, Ln (at least one selected from Nd, Sm, Eu, Gd, or Dy), Ba, Ce, Cu, O
It consists of elements, represented by a compositional formula of La p Ln q Ba r Ce s Cu 9 O 30-z, p, q, r, s are the following conditions p + q + r + s = 12 0 <p <5.5 0.5 <q < An oxide superconducting material that satisfies 7.5 1.5 <r <5.5 0.5 <s <3.5.
ｐ、ｑ、ｒ、ｓが次の条件 1.5＜ｐ＜3.5 2.5＜ｑ＜4.5 ｒ＝４ ｓ＝２ を満たすものである請求項１記載の酸化物超電導材料。(2) Ln is any one of Nd, Sm, Eu and Gd;
2. The oxide superconducting material according to claim 1, wherein p, q, r, and s satisfy the following condition: 1.5 <p <3.5 2.5 <q <4.5 r = 4 s = 2.
たはDyから選ばれた少なくとも一種）、Ba、Ce、Cu、Ｏ
の元素から構成され、組成式がLapLnqBarCesCu9O30-zで
表され、ｐ、ｑ、ｒ、ｓが次の条件 ｐ＋ｑ＋ｒ＋ｓ＝12 ０＜ｐ＜5.5 0.5＜ｑ＜7.5 1.5＜ｒ＜5.5 0.5＜ｓ＜3.5 を満たすものである組成物を、酸素雰囲気で加熱処理を
行って焼結し、加熱処理後、酸素雰囲気中で700℃以下3
00℃以上の温度で熱処理を行って酸素を吸収させること
により、酸化物超電導材料を製造することを特徴とする
酸化物超電導材料の製造方法。3. At least La, Ln (at least one selected from Nd, Sm, Eu, Gd or Dy), Ba, Ce, Cu, O
It consists of elements, represented by a compositional formula of La p Ln q Ba r Ce s Cu 9 O 30-z, p, q, r, s are the following conditions p + q + r + s = 12 0 <p <5.5 0.5 <q < A composition that satisfies 7.5 1.5 <r <5.5 0.5 <s <3.5 is sintered by performing a heat treatment in an oxygen atmosphere, and after the heat treatment, 700 ° C. or less in an oxygen atmosphere.
A method for producing an oxide superconducting material, comprising producing an oxide superconducting material by performing a heat treatment at a temperature of at least 00 ° C. to absorb oxygen.
処理を行って焼結する請求項３記載の酸化物超電導材料
の製造方法。4. The method for producing an oxide superconducting material according to claim 3, wherein the sintering is performed by performing a heat treatment under the condition that the oxygen partial pressure is 0.1 atm or less.
理を行って酸素を吸収させる請求項３記載の酸化物超電
導材料の製造方法。5. The method for producing an oxide superconducting material according to claim 3, wherein a heat treatment is performed under a condition where the oxygen partial pressure exceeds 1 atm to absorb oxygen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1168921A JP2642194B2 (en) | 1989-06-29 | 1989-06-29 | Oxide superconducting material and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1168921A JP2642194B2 (en) | 1989-06-29 | 1989-06-29 | Oxide superconducting material and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0333054A JPH0333054A (en) | 1991-02-13 |
| JP2642194B2 true JP2642194B2 (en) | 1997-08-20 |
Family
ID=15877024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1168921A Expired - Lifetime JP2642194B2 (en) | 1989-06-29 | 1989-06-29 | Oxide superconducting material and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2642194B2 (en) |
-
1989
- 1989-06-29 JP JP1168921A patent/JP2642194B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0333054A (en) | 1991-02-13 |
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