JP3604939B2 - Oxide superconductor and manufacturing method thereof - Google Patents
Oxide superconductor and manufacturing method thereof Download PDFInfo
- Publication number
- JP3604939B2 JP3604939B2 JP03543799A JP3543799A JP3604939B2 JP 3604939 B2 JP3604939 B2 JP 3604939B2 JP 03543799 A JP03543799 A JP 03543799A JP 3543799 A JP3543799 A JP 3543799A JP 3604939 B2 JP3604939 B2 JP 3604939B2
- Authority
- JP
- Japan
- Prior art keywords
- pbo
- oxide superconductor
- thin film
- charge storage
- storage layer
- 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 - Fee Related
Links
Images
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
Description
【０００１】
【産業上の利用分野】
本発明は、酸化物超伝導材料及びその製造方法に関するもので、新規な銅酸化物超伝導体及びその製造方法を提供するものである。
【０００２】
【従来技術】
銅酸化物超伝導体の構造は、１枚もしくは複数枚のＣｕＯ２面と、ＣｕＯ２面にキャリアを供給する電荷溜（またはチャージリザーバー）と呼ばれる層、これらの層を結合するためのアルカリ土類（あるいは希土類）イオン層による交互積層で表される。
【０００３】
銅酸化物超伝導体はこれらの組み合わせにより大まかに分類される。この分類方法には幾種類かあり、４桁数字表記法が良く用いられる（「応用物理」Ｖｏｌ．６６Ｎｏ．４（１９９７）ｐ３２２）。例えば、現在もっとも高い超伝導転移温度（Ｔｃ）を有する、ＨｇＢａ２Ｃａ２Ｃｕ３Ｏ８＋δは、１２２３構造と呼ばれ、４桁数字の最初の数字が電荷溜層の枚数、２番目の数字がアルカリ土類（あるいは希土類）イオン層の枚数、３番目の数字がＣｕＯ２面に挟まれるアルカリ土類（あるいは希土類）イオン層の枚数、４番目の数字がＣｕＯ２面の枚数を表している。例えば、上記ＨｇＢａ２Ｃａ２Ｃｕ３Ｏ８＋δの電荷溜層はＨｇＯであり、Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏ８＋δの電荷溜層は（ＢｉＯ）２である。これまでに、多くの電荷溜層が発見されてきたが、その中で本発明に関連するＰｂを含む電荷溜層では、ＰｂＯ−Ｃｕ−ＰｂＯを電荷溜層とする物質（Ｒ．Ｊ．Ｃａｖａ ｅｔ ａｌ．Ｎａｔｕｒｅ３３６（１９８８）２１１）、ＰｂＯ−Ｃｕを電荷溜層とする物質（Ａ．Ｔｏｋｉｗａ ｅｔ ａｌ． Ｐｈｙｓｉｃａ Ｃ１６１（１９８９）４５９）、または（Ｐｂ，Ｃｕ）Ｏを電荷溜層とする物質（Ｓ．Ｋｏｙａｍａ ｅｔ ａ１． Ｐｈｙｓｉｃａ Ｃ１６６（１９９０）６０２）等が報告されている。しかしながら、ＰｂＯのみを電荷溜層にする銅酸化物超伝導体は発見されていなかった（総合報告として例えば、Ｔ．Ｐ．Ｂｅａｌｅｓ Ｊ．Ｍａｔｅｒ．Ｃｈｅｍ．８（１）（１９９８）ｐ１、常磐ら「固体物理」Ｖｏｌ．２５Ｎｏ．１２（１９９０）ｐ９９５）。
【０００４】
高温超伝導体の応用を考えた場合、超伝導臨界温度（Ｔｃ）が高くて、異方性が小さく、また毒性の強い元素を含まないものが望ましい。しかしながら、高いＴｃを持つ銅酸化物超伝導体、例えばＨｇＢａ２Ｃａ２Ｃｕ３Ｏ８＋δやＴｌ２Ｂａ２Ｃａ２Ｃｕ３Ｏ１０＋δは毒性の強い元素Ｈｇ、Ｔｌを含み、また比較的高いＴｃを持つＢｉ２Ｓｒ２Ｃａ２Ｃｕ３Ｏ１０＋δは異方性が大きいために、実用化には不向きである。ＰｂはＴｌ，Ｈｇに比べ遥かに毒性が低く、鉛蓄電池や圧電セラミクスであるジルコン３鉛（ＰＺＴ）等が日常生活において使用されていることを考えると、Ｐｂを含む超伝導材料は実用化が有望である。また、ＰｂＯ電荷溜層が一枚の場合には、異方性の低下が予想されるため、実用化が容易になると考えられる。さらに、Ｂｉ系やＴｌ系、Ｈｇ系銅酸化物超伝導体において、ＣｕＯ２面が３層の物質がＴｃが高いという経験則から考えると、ＰｂＯを電荷溜層とし、ＣｕＯ２面が３層の構造を持つ物質を合成すれば、高いＴｃを持つ超伝導体が出来る可能性がある。しかしながら、これまでＰｂＯのみを電荷溜層とした銅酸化物超伝導体の作製成功例はない。
【０００５】
【発明が解決しようとする課題】
本発明では超伝導臨界温度（Ｔｃ）が高く、異方性が小さく、また毒性の強い元素を含まないＰｂＯのみを電荷溜層とする新規な銅酸化物超伝導体及びその製造方法を提供することが目的である。
【０００６】
【課題を解決するための手段】
本発明は上述の課題を解決するため、本発明による酸化物超伝導体は、一般式ＰｂＭ２Ｃａｎ−１ＣｕｎＯ２ｎ＋３＋δ、（ＭはＣａ，Ｓｒ，Ｂａのいずれか一種類またはこれらが混合したもので、１≦ｎ≦４，０＜δ≦１）で示され、ＰｂＯを電荷溜層とすることを特徴とする。また、本発明による酸化物超伝導体は、一般式ＰｂＭ ２ Ｓｒ ｎ−１ Ｃｕ ｎ Ｏ ２ｎ＋３＋δ （ＭはＳｒ，Ｂａのいずれか一種類またはこれらが混合したもので、１≦ｎ≦４，０＜δ≦１）で示され、ＰｂＯを電荷溜層とすることを特徴とする。
【０００７】
また、本発明による酸化物超伝導体の製造方法は、一般式ＰｂＭ ２ Ｃａ ｎ−１ Ｃｕ ｎ Ｏ ２ｎ＋３＋δ 、（ＭはＣａ，Ｓｒ，Ｂａのいずれか一種類またはこれらが混合したもので、１≦ｎ≦４，０＜δ≦１）で示され、ＰｂＯを電荷溜層とする酸化物超伝導体の製造方法において、前記一般式を構成する金属を真空容器内で蒸発させ、酸素を導入し、基板温度４５０〜５７０℃の基板に薄膜を成長させることを特徴とする。さらに本発明による酸化物超伝導体の製造方法は、一般式ＰｂＭ ２ Ｓｒ ｎ−１ Ｃｕ ｎ Ｏ ２ｎ＋３＋δ （ＭはＳｒ，Ｂａのいずれか一種類またはこれらが混合したもので、１≦ｎ≦４，０＜δ≦１）で示され、ＰｂＯを電荷溜層とする酸化物超伝導体の製造方法において、前記一般式を構成する金属を真空容器内で蒸発させ、酸素を導入し、基板温度４５０〜５７０℃の基板に薄膜を成長させることを特徴とする。
【０００８】
通常、銅酸化物超伝導体は、酸化物や炭酸塩の粉末を混合、成型し、高温下で反応させる固相反応法により作製される。Ｐｂを含む銅酸化物を合成する場合、固相反応法のような高温下での反応は好ましくなく、その場合には超伝導相ではない物質、例えば、ＳｒＰｂＯ３，Ｓｒ２ＰｂＯ４やＳｒ５Ｐｂ３ＣｕＯ１２等が生成されやすいことが報告されている（例えば、Ｔ．Ｐ．Ｂｅａｌｅｓ Ｊ．Ｍａｔｅｒ．Ｃｈｅｍ．８（１）（１９９８）ｐ１、小池ら「固体物理」ＶｏＩ．２５Ｎｏ．９（１９９０）ｐ５８５）。
【０００９】
また、超伝導体が得られた場合でも、電荷溜層はＰｂＯではなく、ＰｂＯ−Ｃｕ−ＰｂＯ、ＰｂＯ−Ｃｕ、または（Ｐｂ，Ｃｕ）Ｏを電荷溜層とする物質しかできていない。これは高温下での反応であるために、元素の置換等が容易に起こったり、複雑な構造が安定化されることが原因であると考えられる。本発明では、低温下での反応が可能な薄膜法による合成で上記問題を克服する。
【００１０】
【実施例】
以下、本発明の酸化物超伝導材料について実施例にもとづいて、具体的に説明する。
【００１１】
【実施例１】
電子ビーム共蒸着法により、金属のＰｂ，Ｓｒ，Ｃｕ（全て、純度９９．９９％以上）を真空容器内（蒸着前の真空容器内の背圧は１０−８Ｔｏｒｒ以下）で蒸発させ、基板上に１００ｎｍ〜４００ｎｍの厚さで堆積させた。本発明では、基板材料として単結晶のＭｇＯ，ＳｒＴｉＯ３，ＮｄＧａＯ３，ＬａＳｒＧａＯ４，ＬａＡｌＯ３，ＬａＳｒＡｌＯ４，ＹＡｌＯ３の（００１）面（面指数は、立方晶、正方晶の場合にはそのまま、他の場合には疑似立方晶としての（００１）面を示す）を用いた。基板温度は、４５０℃〜５５０℃とした。薄膜成長時には真空容器内にオゾンガスを導入し、薄膜中に過剰酸素を導入した。オゾンガスは分子酸素とともに２ｓｃｃｍの量で供給し（蒸着時の真空容器内の圧力は１．５×１０−５Ｔｏｒｒ程度）、その濃度は７％程度であった。蒸着終了後は、基板温度２００℃程度までオゾンガスを吹き付けた。
【００１２】
図１にＬａＡｌＯ３基板上に作製したＰｂＳｒ２ＣｕＯ５薄膜のＸ線回折図を示す。この図から、薄膜は単一相のｃ軸配向エピタキシャル薄膜であることがわかる。また、電子顕微鏡による格子像観察結果と電子線回折像の結果から、本薄膜の構造は、格子定数ａ０＝ｂ０＝３．８１Å，ｃ０＝８．９３Åのテトラゴナル構造であることが明らかになった。さらに、電子顕微鏡による格子像をシュミレーションと比較した結果、電荷溜層は、ＰｂＯ−Ｃｕ−ＰｂＯや（Ｐｂ，Ｃｕ）Ｏではなく、ＰｂＯのみであることが明らかになった。高周波誘導結合プラズマ発光分光法とヨードメトリー法による組成分析結果では、薄膜組成はＰｂＭ１．０２Ｓｒ１．９５Ｃｕ１．０１Ｏ５．５であった。図２には同じ試料の、電気抵抗率の温度依存性を示す。薄膜のＴｃは３８Ｋであった。磁化率−温度特性を測定した結果、磁化率の符号が３８Ｋから負に転じ、この試料が間違いなく超伝導を示していることが確認された。
【００１３】
他の基板材料を用いた場合にも、超伝導転移が観察された。得られた試料のＴｃを表１に示す。
【００１４】
【表１】
【実施例２】
電子ビーム共蒸着法により、金属のＰｂ，Ｓｒ，Ｃａ，Ｃｕ（全て、純度９９．９９％以上）を真空容器内で蒸発させ、１００ｎｍ〜４００ｎｍの厚さでＰｂＳｒ２Ｃａ１Ｃｕ２Ｏ７薄膜、ＰｂＳｒ２Ｃａ２Ｃｕ３Ｏ９薄膜およびＰｂＳｒ２Ｃａ３Ｃｕ４Ｏ１１薄膜をＳｒＴｉＯ３基板上に作製した。基板温度は、４８０℃〜５７０℃とした、得られた薄膜は全てｃ軸配向エピタキシャル薄膜であり、その組成はそれぞれ、Ｐｂ１．０１Ｓｒ１．９８Ｃａ０．９Ｃｕ２．０２Ｏ７．２、Ｐｂ０．９８Ｓｒ２．０Ｃａ１．９８Ｃｕ３．０Ｏ９．３およびＰｂ１．０２Ｓｒ２．０１Ｃａ２．９７Ｃｕ４．０２Ｏ１１．４であった。表２に得られた薄膜の超伝導臨界温度（Ｔｃ）をまとめた。
【００１６】
【表２】
【実施例３】
上記手法を用いて、金属のＰｂ，Ｂａ，Ｃａ，Ｃｕ（全て、純度９９．９９％以上）を所望の組成で真空容器内で蒸発させ、１００ｎｍ〜４００ｎｍの厚さのＰｂＢａ２Ｃｕ１Ｏ５薄膜、ＰｂＢａ２Ｃａ１Ｃｕ２Ｏ７薄膜、ＰｂＢａ２Ｃａ２Ｃｕ３Ｏ９薄膜およびＰｂＢａ２Ｃａ３Ｃｕ４Ｏ１１薄膜をＮｄＧａＯ３基板上に作製した。基板温度は、４５０℃〜５７０℃とした。得られた薄膜は全てｃ軸配向エピタキシャル薄膜であり、全て超伝導を示した。その組成および超伝導臨界温度（Ｔｃ）を表３に示す。
【００１８】
【表３】
【実施例４】
上記手法を用いて、金属のＰｂ，Ｂａ，Ｓｒ，Ｃｕ（全て、純度９９．９９％以上）を真空容器内で所望の組成で蒸発させ、ｌ００ｎｍ〜４００ｎｍの厚さのＰｂＢａ２Ｃｕ１Ｏ５薄膜、ＰｂＢａ２Ｓｒ１Ｃｕ２Ｏ７薄膜、ＰｂＢａ２Ｓｒ２Ｃｕ３Ｏ９薄膜およびＰｂＢａ２Ｓｒ３Ｃｕ４Ｏ１１薄膜をＬａＳｒＧａＯ４基板上に作製した。基板温度は、４５０℃〜５５０℃とした。得られた薄膜は全てｃ軸配向エピタキシャル薄膜であり、全て超伝導を示した。その組成および超伝導臨界温度（Ｔｃ）を表４に示す。
【００２０】
【表４】
【発明の効果】
以上述べてきたように、本発明によれば、超伝導臨界温度（Ｔｃ）が高く、異方性が小さく、また毒性の強い元素を含まないＰｂＯのみを電荷溜層とする新規な銅酸化物超伝導体及びその製造方法を提供することができる。
【図面の簡単な説明】
【図１】実施例１の手法でＬａＡｌＯ３基板上に作製したＰｂＳｒ２ＣｕＯ５薄膜のＣｕＫαによるＸ線回折パターンを示す図である。
【図２】実施例１の手法でＬａＡｌＯ３基板上に作製したＰｂＳｒ２ＣｕＯ５薄膜の抵抗率−温度特性を示す図である。[0001]
[Industrial applications]
The present invention relates to an oxide superconducting material and a method for producing the same, and provides a novel copper oxide superconductor and a method for producing the same.
[0002]
[Prior art]
Structure of cuprate superconductors, one or a plurality of CuO 2 planes, layer called the charge reservoir for supplying carriers to the two surfaces CuO (or charge reservoir), alkaline earth for binding the layers It is represented by alternate lamination with like (or rare earth) ion layers.
[0003]
Cuprate superconductors are broadly classified by these combinations. There are several kinds of classification methods, and a four-digit numerical notation is often used ("Applied Physics", Vol. 66, No. 4, (1997) p322). For example, HgBa 2 Ca 2 Cu 3 O 8+ δ, which currently has the highest superconducting transition temperature (Tc), is referred to as a 1223 structure, where the first of four digits is the number of charge reservoir layers and the second is Is the number of alkaline earth (or rare earth) ion layers, the third number is the number of alkaline earth (or rare earth) ion layers sandwiched between CuO 2 surfaces, and the fourth number is the number of CuO 2 surfaces. . For example, the charge storage layer of HgBa 2 Ca 2 Cu 3 O 8+ δ is HgO, and the charge storage layer of Bi 2 Sr 2 CaCu 2 O 8+ δ is (BiO) 2 . Many charge storage layers have been discovered so far. Among them, in the charge storage layer containing Pb related to the present invention, a material having PbO-Cu-PbO as a charge storage layer (RJ Cava) is used. et al. Nature 336 (1988) 211), a substance having PbO-Cu as a charge storage layer (A. Tokiwa et al. Physica C161 (1989) 459), or a substance having (Pb, Cu) O as a charge storage layer ( S. Koyama et al., Physica C166 (1990) 602) and the like have been reported. However, a copper oxide superconductor having only PbO as a charge storage layer has not been discovered (for example, as a comprehensive report, TP BEALES J. Mater. Chem. 8 (1) (1998) p1, Joban et al.) "Solid State Physics," Vol. 25 No. 12 (1990) p995).
[0004]
When considering the application of a high-temperature superconductor, it is desirable that the material has a high superconducting critical temperature (Tc), a small anisotropy, and does not contain a highly toxic element. However, a copper oxide superconductor having a high Tc, such as HgBa 2 Ca 2 Cu 3 O 8+ δ or Tl 2 Ba 2 Ca 2 Cu 3 O 10+ δ contains highly toxic elements Hg and Tl and is relatively high. Bi 2 Sr 2 Ca 2 Cu 3 O 10+ δ having Tc is not suitable for practical use because of its large anisotropy. Pb is much less toxic than Tl and Hg. Considering that lead storage batteries and piezoelectric ceramics such as zircon 3 lead (PZT) are used in daily life, superconducting materials containing Pb are not practical. Promising. In the case where the number of the PbO charge storage layers is one, the anisotropy is expected to decrease, and it is considered that practical use is facilitated. Furthermore, in a Bi-based, Tl-based, or Hg-based copper oxide superconductor, a material having three layers of CuO 2 has a high Tc in view of the empirical rule that PbO is used as a charge storage layer and CuO 2 is formed of three layers. By synthesizing a substance having the structure described above, there is a possibility that a superconductor having a high Tc can be obtained. However, there has been no successful production example of a copper oxide superconductor using only PbO as a charge storage layer.
[0005]
[Problems to be solved by the invention]
The present invention provides a novel copper oxide superconductor having a high superconducting critical temperature (Tc), a small anisotropy, and a charge storage layer containing only PbO containing no highly toxic elements, and a method for producing the same. That is the purpose.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an oxide superconductor having a general formula PbM 2 C a n-1 C n O 2n + 3 + δ , wherein M is any one of Ca, Sr, and Ba, or The mixture is represented by 1 ≦ n ≦ 4, 0 <δ ≦ 1), and is characterized by using PbO as a charge storage layer. The oxide superconductor according to the present invention have the general formula PbM is 2 Sr n-1 Cu n O 2n + 3 + δ (M obtained by mixing Sr, any one kind of Ba, or these, 1 ≦ n ≦ 4, 0 <Δ ≦ 1), wherein PbO is used as the charge storage layer.
[0007]
A method of manufacturing an oxide superconductor according to the present invention have the general formula PbM 2 Ca n-1 Cu n O 2n + 3 + δ, (M intended to Ca, Sr, any one kind or these Ba were mixed, 1 .Ltoreq.n.ltoreq.4, 0 <.delta..ltoreq.1), wherein the metal constituting the general formula is evaporated in a vacuum vessel, and oxygen is introduced. The method is characterized in that a thin film is grown on a substrate having a substrate temperature of 450 to 570 ° C. Further method of manufacturing an oxide superconductor according to the present invention have the general formula PbM is 2 Sr n-1 Cu n O 2n + 3 + δ (M obtained by mixing Sr, any one kind of Ba, or these, 1 ≦ n ≦ 4 , 0 <δ ≦ 1), wherein the metal constituting the general formula is evaporated in a vacuum vessel, oxygen is introduced, and the substrate temperature is reduced. The method is characterized in that a thin film is grown on a substrate at 450 to 570 ° C.
[0008]
In general, a copper oxide superconductor is produced by a solid-phase reaction method in which oxide and carbonate powders are mixed, molded, and reacted at a high temperature. When synthesizing a copper oxide containing Pb, a reaction at a high temperature such as a solid phase reaction method is not preferable. In this case, a substance that is not a superconducting phase, for example, SrPbO 3 , Sr 2 PbO 4, or Sr 5 It has been reported that Pb 3 CuO 12 and the like are likely to be produced (for example, TP BEALES J. Mater. Chem. 8 (1) (1998) p1, Koike et al., “Solid State Physics” VoI.25No.9 ( 1990) p585).
[0009]
In addition, even when a superconductor is obtained, the charge storage layer is made of only PbO-Cu-PbO, PbO-Cu, or (Pb, Cu) O as a charge storage layer instead of PbO. This is considered to be due to the fact that the reaction is carried out at a high temperature, so that the substitution of elements or the like easily occurs or a complicated structure is stabilized. In the present invention, the above-mentioned problem is overcome by the synthesis using a thin film method capable of reacting at a low temperature.
[0010]
【Example】
Hereinafter, the oxide superconducting material of the present invention will be specifically described based on examples.
[0011]
Embodiment 1
The metal Pb, Sr, and Cu (all of which have a purity of 99.99% or more) are evaporated in a vacuum vessel (the back pressure in the vacuum vessel before the vapor deposition is 10-8 Torr or less) by an electron beam co-evaporation method. Deposited on top with a thickness of 100-400 nm. In the present invention, the (001) plane of a single crystal of MgO, SrTiO 3 , NdGaO 3 , LaSrGaO 4 , LaAlO 3 , LaSrAlO 4 , and YAlO 3 as a substrate material (the plane index is cubic or tetragonal, In other cases, a (001) plane as a pseudo cubic crystal was used. The substrate temperature was 450 ° C. to 550 ° C. During the growth of the thin film, ozone gas was introduced into the vacuum vessel, and excess oxygen was introduced into the thin film. Ozone gas was supplied together with molecular oxygen in an amount of 2 sccm (the pressure in the vacuum vessel at the time of vapor deposition was about 1.5 × 10 −5 Torr), and the concentration was about 7%. After the vapor deposition, ozone gas was blown to a substrate temperature of about 200 ° C.
[0012]
FIG. 1 shows an X-ray diffraction diagram of a PbSr 2 CuO 5 thin film formed on a LaAlO 3 substrate. This figure shows that the thin film is a single-phase c-axis oriented epitaxial thin film. Further, from the result of observation of the lattice image with an electron microscope and the result of the electron beam diffraction image, it is clear that the structure of the present thin film is a tetragonal structure with lattice constants a 0 = b 0 = 3.81 ° and c 0 = 8.93 °. Became. Furthermore, as a result of comparing the lattice image obtained by the electron microscope with the simulation, it was found that the charge storage layer was not PbO-Cu-PbO or (Pb, Cu) O but only PbO. In the result of composition analysis by high-frequency inductively coupled plasma emission spectroscopy and iodometry, the thin film composition was PbM 1.02 Sr 1.95 Cu 1.01 O 5.5 . FIG. 2 shows the temperature dependence of the electrical resistivity of the same sample. The Tc of the thin film was 38K. As a result of measuring the susceptibility-temperature characteristics, the sign of the susceptibility changed from 38 K to negative, and it was confirmed that this sample definitely showed superconductivity.
[0013]
Superconducting transition was also observed when other substrate materials were used. Table 1 shows Tc of the obtained sample.
[0014]
[Table 1]
Embodiment 2
Pb, Sr, Ca, and Cu (all of which have a purity of 99.99% or more) are evaporated in a vacuum vessel by an electron beam co-evaporation method, and a PbSr 2 Ca 1 Cu 2 O 7 thin film having a thickness of 100 nm to 400 nm is formed. , A PbSr 2 Ca 2 Cu 3 O 9 thin film and a PbSr 2 Ca 3 Cu 4 O 11 thin film were formed on a SrTiO 3 substrate. The substrate temperature was 480 ° C. to 570 ° C., and all the obtained thin films were c-axis oriented epitaxial thin films, each having a composition of Pb 1.01 Sr 1.98 Ca 0.9 Cu 2.02 O 7. 2 , Pb 0.98 Sr 2.0 Ca 1.98 Cu 3.0 O 9.3 and Pb 1.02 Sr 2.01 Ca 2.97 Cu 4.02 O 11.4 . Table 2 summarizes the superconducting critical temperature (Tc) of the obtained thin films.
[0016]
[Table 2]
Embodiment 3
Using the above technique, Pb, Ba, Ca, and Cu (all of which have a purity of 99.99% or more) are evaporated in a vacuum vessel with a desired composition, and a PbBa 2 Cu 1 O 5 having a thickness of 100 nm to 400 nm is obtained. A thin film, a PbBa 2 Ca 1 Cu 2 O 7 thin film, a PbBa 2 Ca 2 Cu 3 O 9 thin film, and a PbBa 2 Ca 3 Cu 4 O 11 thin film were formed on an NdGaO 3 substrate. The substrate temperature was 450 ° C. to 570 ° C. All of the obtained thin films were c-axis oriented epitaxial thin films, and all exhibited superconductivity. Table 3 shows the composition and the superconducting critical temperature (Tc).
[0018]
[Table 3]
Embodiment 4
Using the above method, Pb, Ba, Sr, and Cu (all of which have a purity of 99.99% or more) are evaporated to a desired composition in a vacuum vessel, and a PbBa 2 Cu 1 O 5 having a thickness of 100 nm to 400 nm is evaporated. Thin films, PbBa 2 Sr 1 Cu 2 O 7 thin films, PbBa 2 Sr 2 Cu 3 O 9 thin films, and PbBa 2 Sr 3 Cu 4 O 11 thin films were formed on a LaSrGaO 4 substrate. The substrate temperature was 450 ° C. to 550 ° C. All of the obtained thin films were c-axis oriented epitaxial thin films, and all exhibited superconductivity. Table 4 shows the composition and the superconducting critical temperature (Tc).
[0020]
[Table 4]
【The invention's effect】
As described above, according to the present invention, a novel copper oxide having a high superconducting critical temperature (Tc), a small anisotropy, and using only PbO containing no highly toxic element as a charge storage layer A superconductor and a method for manufacturing the same can be provided.
[Brief description of the drawings]
FIG. 1 is a view showing an X-ray diffraction pattern by CuKα of a PbSr 2 CuO 5 thin film formed on a LaAlO 3 substrate by the method of Example 1.
FIG. 2 is a diagram showing a resistivity-temperature characteristic of a PbSr 2 CuO 5 thin film formed on a LaAlO 3 substrate by the method of Example 1.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03543799A JP3604939B2 (en) | 1999-02-15 | 1999-02-15 | Oxide superconductor and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03543799A JP3604939B2 (en) | 1999-02-15 | 1999-02-15 | Oxide superconductor and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000233926A JP2000233926A (en) | 2000-08-29 |
| JP3604939B2 true JP3604939B2 (en) | 2004-12-22 |
Family
ID=12441837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03543799A Expired - Fee Related JP3604939B2 (en) | 1999-02-15 | 1999-02-15 | Oxide superconductor and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3604939B2 (en) |
-
1999
- 1999-02-15 JP JP03543799A patent/JP3604939B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000233926A (en) | 2000-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Eom et al. | Single-Crystal Epitaxial Thin Films of the Isotropic Metallic Oxides Sr1–x Ca x RuO3 (0≤×≤ 1) | |
| US5310707A (en) | Substrate material for the preparation of oxide superconductors | |
| US5439876A (en) | Method of making artificial layered high Tc superconductors | |
| US4962086A (en) | High Tc superconductor - gallate crystal structures | |
| Schuller et al. | Structure of high Tc oxide superconductors | |
| Mercey et al. | Thin film deposition: a novel synthetic route to new materials | |
| JP3089294B2 (en) | Manufacturing method of superconducting tape material | |
| JP2933225B2 (en) | Metal oxide material | |
| US5578551A (en) | Method for synthesis of high-temperature Hg-Ba-Ca-Cu-O (HBCCO) superconductors | |
| JPH10236821A (en) | Low-anisotropy high-temperature superconductor based on uncertainty principle and its production | |
| JP3604939B2 (en) | Oxide superconductor and manufacturing method thereof | |
| JP2950422B2 (en) | Metal oxide material | |
| Biswas et al. | Epitaxial conducting ABO3 perovskite oxide thin films | |
| Karimoto et al. | New superconducting PbSr2CuO5+ δ prepared by a novel low-temperature synthetic route using molecular beam epitaxy | |
| Gupta | Thin film synthesis of metastable and artificially structured oxides | |
| JP3787572B2 (en) | Selective reduction type high temperature superconductor and method for producing the same | |
| JP2555505B2 (en) | Metal oxide material | |
| JP2519337B2 (en) | Substrate material for producing oxide superconductor and method for producing oxide superconductor | |
| Koller et al. | Epitaxial growth and properties of (CO3) stabilised BaCuO2 superconducting thin films | |
| JPH03275504A (en) | Oxide superconductor thin film and its production | |
| Norton | Epitaxial growth of superconducting cuprate thin films | |
| Kyu-Jeong et al. | Fabrication of High-Quality $ SmBa_ {2} Cu_ {3} O_ {7-{\delta}} $ Thin Films by a Modified TFA-MOD Process | |
| Lim et al. | Fabrication of YBCO film approached by the ‘211 process’ in the TFA-MOD method | |
| JP2003257709A (en) | Perovskite-containing laminar compound laminate, element using the same, and electronic device | |
| WO2004059753A1 (en) | Oxide superconducting thin film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040323 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040524 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20040524 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040921 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040930 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071008 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081008 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091008 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101008 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101008 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111008 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111008 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121008 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121008 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131008 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |