JPH01141869A - Production of superconductor - Google Patents
Production of superconductorInfo
- Publication number
- JPH01141869A JPH01141869A JP62299491A JP29949187A JPH01141869A JP H01141869 A JPH01141869 A JP H01141869A JP 62299491 A JP62299491 A JP 62299491A JP 29949187 A JP29949187 A JP 29949187A JP H01141869 A JPH01141869 A JP H01141869A
- Authority
- JP
- Japan
- Prior art keywords
- dry
- atmosphere
- superconductor
- sintered body
- dehydrated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002887 superconductor Substances 0.000 title claims abstract description 16
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000000843 powder Substances 0.000 claims abstract description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000001301 oxygen Substances 0.000 claims abstract description 13
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 13
- 238000010438 heat treatment Methods 0.000 claims abstract description 12
- 229910052747 lanthanoid Inorganic materials 0.000 claims abstract description 6
- 150000002602 lanthanoids Chemical class 0.000 claims abstract description 6
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 5
- 239000000203 mixture Substances 0.000 claims abstract description 3
- 229910052706 scandium Inorganic materials 0.000 claims abstract description 3
- 229910002480 Cu-O Inorganic materials 0.000 claims abstract 2
- 239000002994 raw material Substances 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 9
- 230000002159 abnormal effect Effects 0.000 abstract description 5
- 238000005245 sintering Methods 0.000 abstract description 5
- 229910052788 barium Inorganic materials 0.000 abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 3
- 150000004649 carbonic acid derivatives Chemical class 0.000 abstract description 2
- 229910052802 copper Inorganic materials 0.000 abstract description 2
- 239000007858 starting material Substances 0.000 abstract 2
- 229910052746 lanthanum Inorganic materials 0.000 abstract 1
- 238000010304 firing Methods 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 5
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- 239000002274 desiccant Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はＬｎ、 Ｂａ、 Ｃｕ （ＬｎはＹ、Ｓｃ、Ｌ
ａ及びランタニド元素）の酸化物を主成分とする超電導
体の製造方法に関し、特に臨界電流密度（Ｊｃ）及び臨
界温度（Ｔｃ）を高くした超電導体の製造方法に関する
。[Detailed description of the invention] [Industrial application field] The present invention is based on Ln, Ba, Cu (Ln is Y, Sc, L
The present invention relates to a method of manufacturing a superconductor containing oxides of oxides of a and lanthanide elements as main components, and particularly relates to a method of manufacturing a superconductor with high critical current density (Jc) and critical temperature (Tc).
（従来の技術）
ＬｎかＹである場合を例にとると、その製造法はＹ２Ｏ
３、Ｂ、ＧＯ３、ＣｕＯ粉末をＹ ： ８ａ ： Ｃｕ
の原子比でｌ：２：３の割合に混合し、まず８００〜９
００℃て予備焼成し１反応させる。これを粉砕し、成形
して８５０〜９５０”Ｃて焼成し焼結体とする。この焼
結体は、このままでは臨界温度（Ｔｃ）が低いので、空
気中もしくは酸素ガス中で低い温度（３００〜４００℃
）て熱処理してＴｃを高くしていた。(Prior art) Taking the case of Ln or Y as an example, the manufacturing method is Y2O
3. B, GO3, CuO powder Y: 8a: Cu
Mix at an atomic ratio of 1:2:3, and first add 800 to 9
Preliminary firing was carried out at 00°C and one reaction was carried out. This is crushed, molded, and fired at 850 to 950"C to form a sintered body. This sintered body has a low critical temperature (Tc) in the air or oxygen gas (300"C). ~400℃
) to increase Tc.
従来の研究により、組成式ＹＢａｔＣｕＪｘにおいてＸ
が、焼成直後で６．５以下であるものが、熱処理するこ
とにより ７に近づき、それと共にＴｃが上昇すること
か解っていた。According to previous research, in the compositional formula YBatCuJx,
However, it was known that the value of 6.5 or less immediately after firing approaches 7 by heat treatment, and the Tc increases accordingly.
実用上、超電導体Ｔｃ及びＪｃが共に高いことが望まし
い、高いＪｃを持つ超電導体を得るためには。Practically, it is desirable that both Tc and Jc of the superconductor are high, in order to obtain a superconductor with high Jc.
気孔率が小さく、嵩密度め高い焼結体であることか好ま
しい、しかしながら、一般に気孔率の小さな焼結体を熱
処理しようとすると、十分な酸素濃度を得るために長時
間を要し、しばしば、 ４００°Ｃ以下の温度に１００
時間以上も維持しなければならない。しかるに本発明者
らの研究によると、このような低い温度に長時間保持す
ると、焼結体の粒界に異常現象が生じ、結果的に高い電
流密度が得られないことが解っている。従って従来の方
法では、十分高い酸素濃度と、高い嵩密度の両立が困難
であり、その結果Ｔｃ及びＪｃを共に最適化することが
出来なかった。。A sintered body with low porosity and high bulk density is preferable.However, when attempting to heat treat a sintered body with low porosity, it generally takes a long time to obtain a sufficient oxygen concentration, and often 100 at temperatures below 400°C
Must be maintained over time. However, according to research conducted by the present inventors, it has been found that if the temperature is kept at such a low temperature for a long time, an abnormal phenomenon occurs in the grain boundaries of the sintered body, and as a result, a high current density cannot be obtained. Therefore, in the conventional method, it is difficult to achieve both a sufficiently high oxygen concentration and a high bulk density, and as a result, it is not possible to optimize both Tc and Jc. .
本発明はＬｎＢａ＊Ｃｕ、０．系の超電導体において、
長時間熱処理しても、粒界の異常現象を生じさせないよ
うな超電導体の製造方法に関するものである。The present invention is based on LnBa*Cu, 0. In the system superconductor,
The present invention relates to a method for producing a superconductor that does not cause abnormal grain boundary phenomena even after long-term heat treatment.
（問題点を解決するための手段）
本発明者は、上記目的のために種々研究した結果、粒界
の異常現象が水分にもとづくことを見出し、焼成前に、
原料中の水分を十分少なくし、その後の焼成・熱処理工
程を乾燥酸素、または乾燥空気雰囲気中で行うことによ
って、熱処理中に粒界に異常現象が生じるのが防止でき
ることを発見し、本発明に至った。(Means for Solving the Problem) As a result of various studies for the above purpose, the present inventor discovered that the abnormal phenomenon of grain boundaries is based on moisture, and that
It was discovered that abnormal phenomena occurring at grain boundaries during heat treatment can be prevented by sufficiently reducing the moisture content in the raw materials and performing the subsequent firing and heat treatment steps in a dry oxygen or dry air atmosphere. It's arrived.
即ち本発明は、 Ｌｎ−Ｈａ−Ｃｕ−０系（ＬｎはＹ、
Ｓｃ、Ｌａ及びランタニド元素、もしくはそれらの混合
物）超電導体を製造する方法において、脱水した原料粉
末を乾燥雰囲気で焼結した後、乾燥酸素、もしくは乾燥
空気雰囲気中で熱処理することを特徴とする超電導体の
製造方法である。ここでＬｎ −Ｂａ−Ｃｕ−０系超電
導体とは、Ｌｎ −Ｈａ −Ｃｕ −０を主成分とする
焼結体をいい、例えばこれにＳｒ、 Ｃａ等を添加した
ものをも含む。That is, the present invention is based on the Ln-Ha-Cu-0 system (Ln is Y,
Sc, La, and lanthanide elements, or mixtures thereof) A method for producing a superconductor, characterized in that dehydrated raw material powder is sintered in a dry atmosphere and then heat-treated in a dry oxygen or dry air atmosphere. It is a method of manufacturing the body. Here, the Ln-Ba-Cu-0 superconductor refers to a sintered body containing Ln-Ha-Cu-0 as a main component, and includes, for example, a sintered body to which Sr, Ca, etc. are added.
原ネ１粉末とは、焼結工程の原料としての粉末をいい、
１、ｎかＹである場合を例にとれば、イツトリウム、バ
リウム、銅の酸化物、炭酸塩等の無機の、これらを予備
焼成しＹＢａ＊ＣｕＪｘとした後粉砕したもの等をいう
。Raw material 1 powder refers to powder used as a raw material for the sintering process.
For example, in the case of 1, n or Y, it refers to inorganic materials such as yttrium, barium, copper oxides, carbonates, etc., which are pre-calcined to form YBa*CuJx and then pulverized.
脱水は、原料粉末を例えば真空中で、摂氏数百度の高温
で数時間加熱して行う。この操作は成形、焼成中又は焼
成後に行っても焼結成形体が形成されていて脱水の効果
が少ないのて、焼成工程の前の段階で行なう必要があり
、予備焼成の前に行なうのが望ましく、以後は乾燥状態
（乾燥雰囲気又は真空）に維持しておく必要がある。乾
燥雰囲気は、ガス中の水分が２１ｇ／ｄａ’以下好まし
くは０．２■ｇ／ｄａ”以下である。Dehydration is performed by heating the raw material powder, for example, in a vacuum at a high temperature of several hundred degrees Celsius for several hours. Even if this operation is performed during or after shaping and firing, the sintered compact is still formed and the effect of dehydration is small, so it must be performed at a stage before the firing process, and it is preferable to perform it before pre-firing. After that, it is necessary to maintain it in a dry state (dry atmosphere or vacuum). In the drying atmosphere, the moisture content in the gas is 21 g/da' or less, preferably 0.2 g/da' or less.
ガスの除湿は１通常とられる方法シリカゲル、塩化カル
シウムなどの乾燥剤層を通すとかコールドトラップによ
るなどを適宜採用できる。The gas can be dehumidified by one of the usual methods, such as passing it through a layer of desiccant such as silica gel or calcium chloride, or using a cold trap.
脱水した原料粉末は、乾燥雰囲気下で混合成形する。The dehydrated raw material powders are mixed and molded in a dry atmosphere.
また’７２０１． ＢａＣＯ３、ＣｕＯ粉末を混合し
た後真空中で加熱脱水し、上記同様成形してもよい、ま
た本発明において脱水した原料には初めから水分を含ん
でない原料も含まれ、これは脱水工程は不要である。Also '7201. After mixing BaCO3 and CuO powders, they may be heated and dehydrated in a vacuum and then molded in the same manner as above.Also, the dehydrated raw materials in the present invention include raw materials that do not contain water from the beginning, and the dehydration step is not necessary. be.
いずれ°にしても、焼結工程前の原料粉末が脱水された
状態て維持されていればよい。In any case, it is sufficient that the raw material powder before the sintering step is maintained in a dehydrated state.
成形体は次に乾燥雰囲気で焼成する。この焼成で成形体
は焼結する。この条件は乾燥した空気中或いは酸素ガス
などの雰囲気中て行ない、温度は８５０〜９５０℃の範
囲が通常である。The compact is then fired in a dry atmosphere. The molded body is sintered by this firing. This condition is carried out in dry air or in an atmosphere of oxygen gas, etc., and the temperature is usually in the range of 850 to 950°C.
乾燥雰囲気は、前述のように雰囲気ガスを、乾燥剤やコ
ールドトラップにより除湿して作られる。このようにし
て作られた焼結体は、乾燥酸素雰囲気中で熱処理される
。この熱処理は、焼結体の酸素濃度を高めＴｃ及びＪｃ
を高めるためになされる。このように脱水した原料粉末
を用い、乾燥状態で焼結した焼結体を、乾燥酸素雰囲気
（乾燥空気中でもよい）中で熱処理することにより従来
みられた粒界の異常現象をおこすことなく酸素濃度を上
げることができるので超電導体のＴｃ及びＪｃを高める
ことができる。The dry atmosphere is created by dehumidifying the atmospheric gas using a desiccant or a cold trap, as described above. The sintered body thus produced is heat treated in a dry oxygen atmosphere. This heat treatment increases the oxygen concentration of the sintered body and increases Tc and Jc.
It is done to increase the By using the raw material powder dehydrated in this way and sintering the sintered body in a dry state, heat treatment is performed in a dry oxygen atmosphere (dry air may also be used). Since the concentration can be increased, the Tc and Jc of the superconductor can be increased.
熱処理の過程で水分がどのように作用するかは明らかで
ないが、焼結体の粒界に蓄積し少ない場合にはジョセフ
ソン弱結合を与え、甚だしい場合には異質な相を作るも
のと推定される。Although it is not clear how moisture acts during the heat treatment process, it is presumed that it accumulates at the grain boundaries of the sintered body, causing weak Josephson bonding in cases where it is small, and in severe cases forming heterogeneous phases. Ru.
以下実施例により本発明をさらに詳細に説明する。The present invention will be explained in more detail with reference to Examples below.
実施例
ＹｔＯｚ、 ＢａＣＯ３，ＣｕＯ粉末をＹ：Ｂａ：Ｃ
ｕの原子比で１：２：３に秤量し混合した。これを真空
中で（５ｘ １０−’Ｔｏｒｒ）徐々に昇温し、７００
℃で３時間脱水した。これを乾燥剤ＣａＣ１ｇを通した
乾燥酸素（＋１２０含有量０．２＋＊ｇ／ｄａ’以下）
中９００℃で２５時間予備焼成した。これを乾燥窒素中
で直径２０ｍｍ厚さ１１１層のディスクに成形し、乾燥
酸素中９３０℃で２０時焼成し焼結体とした。この焼結
体を、乾燥酸素、１００℃／ｈｒて３００℃まで冷却し
、更に３００℃て１００時間熱処理を行った。Example YtOz, BaCO3, CuO powder Y:Ba:C
They were weighed and mixed at an atomic ratio of 1:2:3. This was gradually heated in vacuum (5 x 10-'Torr) to 700
It was dehydrated at ℃ for 3 hours. Dry oxygen (+120 content 0.2+*g/da' or less) passed through 1g of desiccant CaC
Preliminary firing was performed at 900° C. for 25 hours. This was formed into a disk having a diameter of 20 mm and a thickness of 111 layers in dry nitrogen, and was fired at 930° C. for 20 hours in dry oxygen to obtain a sintered body. This sintered body was cooled to 300°C using dry oxygen at 100°C/hr, and then heat-treated at 300°C for 100 hours.
比較例
Ｙ２Ｏ１、ＢａＣ０＋、ＣｕＯ粉末をＹ：Ｂａ：Ｃｕの
原子比て１：２：３に秤量し混合した。これを大気中９
００℃で予備焼成し、粉砕混合することを３回繰り返し
、のべ２５時間予備焼成した。これを、直径２０■、厚
さｌａｍのディスク状に成形し、大気中９３０℃で２０
時間焼成し焼結体とした。この焼結体を、大気中、１０
０℃／ｈｒで３００℃まで冷却し、更に３００℃で１０
０時間熱処理を行った。Comparative Example Y2O1, BaC0+, and CuO powders were weighed and mixed at an atomic ratio of Y:Ba:Cu of 1:2:3. 9 in the atmosphere
Preliminary firing at 00°C, pulverization and mixing were repeated three times, and preliminary firing was carried out for a total of 25 hours. This was formed into a disk shape with a diameter of 20 cm and a thickness of lam, and heated at 930°C in the atmosphere for 20 minutes.
A sintered body was obtained by firing for several hours. This sintered body was placed in the atmosphere for 10
Cool to 300°C at 0°C/hr, and then cool for 10 minutes at 300°C.
Heat treatment was performed for 0 hours.
従来法で製造した焼結体と、本発明による方法で製造し
た焼結体の臨界温度Ｔｃと、液体窒素温度７７Ｋに於け
る臨界電流密度Ｊｃを通電法により、端子間電圧に１Ｉ
Ｌｖの有意電圧が観測される電流値を基準として測定し
た結果を表１に示す。The critical temperature Tc of the sintered body manufactured by the conventional method and the sintered body manufactured by the method of the present invention, and the critical current density Jc at a liquid nitrogen temperature of 77K were determined by the current flow method to increase the terminal voltage to 1I.
Table 1 shows the measurement results based on the current value at which a significant voltage of Lv was observed.
表 １ Ｔｃの測定は、以下のようにして行った。Table 1 The measurement of Tc was performed as follows.
試験片を長さ２０■１幅３■Ｉに切り出し、直流四端子
法により測定した。試験片を約１”Ｃ／分の速度で温度
を下げ、約１’Ｃおきに、両側端子より・３ｍＡの電流
を導入し、内側２端子に現れる電圧を測定し、電圧の値
が測定下限（１，Ｏｘ １０−’Ｖ ）を切ったところ
で抵抗な０とし、その温度をＴｃとした。A test piece was cut out to a length of 20 cm and width of 3 cm, and measured by the DC four-terminal method. Lower the temperature of the test piece at a rate of approximately 1"C/min, introduce a current of 3mA from both terminals at approximately 1'C intervals, and measure the voltage appearing at the two inner terminals. The voltage value is the lower measurement limit. (1,Ox 10-'V) was set as zero resistance, and the temperature was set as Tc.
Ｊｃの測定は、以下のようにして行った。The measurement of Jc was performed as follows.
前述の試験片を液体窒素中にひたし、温度７７゜Ｋ中で
両側端子より導入する電流を増加しながら、内側２端子
に現れる電圧を測定し、電圧の値か測定下限（１，Ｏｘ
１０−’Ｖ ）より大きくなったところの導入した電
流の値を断面積で除算しＪｃとした。The aforementioned test piece was immersed in liquid nitrogen, and the voltage appearing at the two inner terminals was measured while increasing the current introduced from both terminals at a temperature of 77°K.
The value of the introduced current that became larger than 10-'V) was divided by the cross-sectional area and was determined as Jc.
表１で明らかなように、本発明による方法では、従来法
に比べＪｃが約１０倍増加した。As is clear from Table 1, the method according to the present invention increased Jc by about 10 times compared to the conventional method.
本発明によれば、Ｌｎ −Ｂａ −Ｃｕ −０系超電導
体製造用の原料として、脱水した原料粉末を用い、以後
の焼結、熱処理を乾燥した雰囲気において行うことによ
り、高いＴｃを維持しつつ、高いＪｃの超電導体を得る
ことができる。According to the present invention, dehydrated raw material powder is used as a raw material for manufacturing Ln-Ba-Cu-0 based superconductors, and the subsequent sintering and heat treatment are performed in a dry atmosphere, thereby maintaining a high Tc. , a high Jc superconductor can be obtained.
なお、Ｊｃ、 Ｔｃの値は各所で発表されているが。Note that the values of Jc and Tc are announced in various places.
試料の作成条件等により多少の変動があるので。There may be slight variations depending on the sample preparation conditions, etc.
絶対値で比較することは適当でない、他の条件をできる
だけ一定にして相対的に比較することが重要である。It is not appropriate to compare absolute values; it is important to keep other conditions as constant as possible and compare relatively.
Claims (1)
ランタニド元素、もしくはそれらの混合物）超電導体を
製造する方法において、脱水した原料粉末を乾燥雰囲気
で焼結し、生成した焼結体を乾燥酸素雰囲気て熱処理す
ることを特徴とする超電導体の製造方法。In a method for manufacturing Ln_1Ba-Cu-O system (Ln is Y, Sc, La, and lanthanide elements, or a mixture thereof) superconductor, dehydrated raw material powder is sintered in a dry atmosphere, and the resulting sintered body is dried. A method for producing a superconductor, characterized by heat treatment in an oxygen atmosphere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62299491A JPH01141869A (en) | 1987-11-27 | 1987-11-27 | Production of superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62299491A JPH01141869A (en) | 1987-11-27 | 1987-11-27 | Production of superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01141869A true JPH01141869A (en) | 1989-06-02 |
Family
ID=17873257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62299491A Pending JPH01141869A (en) | 1987-11-27 | 1987-11-27 | Production of superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01141869A (en) |
-
1987
- 1987-11-27 JP JP62299491A patent/JPH01141869A/en active Pending
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