JPH04292415A - Metal oxide material - Google Patents
Metal oxide materialInfo
- Publication number
- JPH04292415A JPH04292415A JP3077143A JP7714391A JPH04292415A JP H04292415 A JPH04292415 A JP H04292415A JP 3077143 A JP3077143 A JP 3077143A JP 7714391 A JP7714391 A JP 7714391A JP H04292415 A JPH04292415 A JP H04292415A
- Authority
- JP
- Japan
- Prior art keywords
- present
- metal oxide
- oxide material
- angstroms
- tunnel barrier
- 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
- 239000000463 material Substances 0.000 title claims abstract description 37
- 229910044991 metal oxide Inorganic materials 0.000 title claims abstract description 12
- 150000004706 metal oxides Chemical class 0.000 title claims abstract description 12
- 229910052692 Dysprosium Inorganic materials 0.000 claims abstract description 5
- 229910052689 Holmium Inorganic materials 0.000 claims abstract description 5
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 5
- 239000000203 mixture Substances 0.000 claims description 9
- 239000013078 crystal Substances 0.000 claims description 7
- 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 claims description 3
- 239000002887 superconductor Substances 0.000 abstract description 17
- 230000004888 barrier function Effects 0.000 abstract description 14
- 229910052712 strontium Inorganic materials 0.000 abstract description 9
- 239000000758 substrate Substances 0.000 abstract description 9
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 239000002994 raw material Substances 0.000 description 8
- 239000005751 Copper oxide Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229910000431 copper oxide Inorganic materials 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- NLQFUUYNQFMIJW-UHFFFAOYSA-N dysprosium(III) oxide Inorganic materials O=[Dy]O[Dy]=O NLQFUUYNQFMIJW-UHFFFAOYSA-N 0.000 description 2
- VQCBHWLJZDBHOS-UHFFFAOYSA-N erbium(III) oxide Inorganic materials O=[Er]O[Er]=O VQCBHWLJZDBHOS-UHFFFAOYSA-N 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910002229 La2−xSrxCuO4 Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- JYTUFVYWTIKZGR-UHFFFAOYSA-N holmium oxide Inorganic materials [O][Ho]O[Ho][O] JYTUFVYWTIKZGR-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum oxide Inorganic materials [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- KTUFCUMIWABKDW-UHFFFAOYSA-N oxo(oxolanthaniooxy)lanthanum Chemical compound O=[La]O[La]=O KTUFCUMIWABKDW-UHFFFAOYSA-N 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- LEDMRZGFZIAGGB-UHFFFAOYSA-L strontium carbonate Chemical compound [Sr+2].[O-]C([O-])=O LEDMRZGFZIAGGB-UHFFFAOYSA-L 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 229910001427 strontium ion Inorganic materials 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明を主に銅の酸化物超伝導材
料と隣接して有効利用出来る金属酸化物材料に関し、特
に超伝導電子素子を作製する際の素子の基板若しくは基
板と超伝導体との間のバッファー層及び超伝導体と金属
又は超伝導体の間の絶縁層として有用で金属酸化物材料
に関する。[Industrial Application Field] The present invention mainly relates to a metal oxide material that can be effectively used adjacent to a copper oxide superconducting material, and in particular, the present invention relates to a substrate of an element when manufacturing a superconducting electronic device, or a superconducting substrate and a superconducting material. The present invention relates to metal oxide materials useful as buffer layers between bodies and insulating layers between superconductors and metals or superconductors.
【０００２】0002
【従来の技術】近年、相次いで発見された銅を含む酸化
物超伝導体は、従来知られていたニオブ系等の超伝導臨
界温度（Ｔｃ）を大きく上回るＴｃを持つ為、多くの分
野で応用研究が進められている。超伝導エレクトロニク
スの分野においても、その実用化への期待は大きく多く
の研究報告が既に発表されている。超伝導エレクトロニ
クス素子に用いられる超伝導体は薄膜作製技術により達
成するのが一般的であるが、素子を形成する為には超伝
導体だけではなく、トンネルバリア層からバッファ層、
基板等の材料も適切なものでなければならない。これら
の材料を選ぶ場合、超伝導体と良好な界面を得ることが
重大なポイントであるが、その為には超伝導体の格子定
数とそれに接合するトンネルバリア層やバッファ層、基
板等の格子定数が一致していることが望ましい。又、両
者の熱膨張係数も近いことが望ましい。更には高温中で
成膜する場合や高温中のプロセスを通す場合、両者の元
素が拡散することが多いが、この拡散が起こりにくい材
料若しくは拡散が起こっても素子に影響が少ない材料を
選ぶことが必要である。この様な素子としては、ＹＢａ
２Ｃｕ３Ｏｙに、これと同じ構造を持つＰｒＢａ２Ｃｕ
３Ｏｙをトンネルバリア層材料として組み合わせたもの
が提案されている。[Prior Art] Copper-containing oxide superconductors that have been discovered one after another in recent years have a Tc much higher than the superconducting critical temperature (Tc) of conventionally known niobium-based superconductors, so they are used in many fields. Applied research is underway. In the field of superconducting electronics, there are great expectations for its practical application, and many research reports have already been published. Superconductors used in superconducting electronic devices are generally achieved using thin film fabrication technology, but in order to form devices, not only superconductors are used, but also layers such as tunnel barrier layers, buffer layers, etc.
Materials such as the substrate must also be suitable. When selecting these materials, it is important to obtain a good interface with the superconductor, but for this purpose, the lattice constant of the superconductor and the lattice of the tunnel barrier layer, buffer layer, substrate, etc. It is desirable that the constants match. Further, it is desirable that the coefficients of thermal expansion of both materials be close to each other. Furthermore, when forming a film at high temperatures or passing through a process at high temperatures, both elements often diffuse, but it is important to choose a material that is unlikely to cause this diffusion or a material that will have little effect on the device even if diffusion occurs. is necessary. As such an element, YBa
2Cu3Oy has the same structure as PrBa2Cu
A combination of 3Oy as a tunnel barrier layer material has been proposed.
【０００３】0003
【発明が解決しようとしている課題】超伝導体としてＬ
ａ２−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ、Ｂａ）やＬａ
２−ｘＳｒｘＣａＣｕ２Ｏｙ等を利用しようとした場合
、トンネルバリア層としては半導体であるＬａ２ＣｕＯ
ｙ、Ｎｄ２ＣｕＯｙ等が候補として挙げられる。しかし
ながら、Ｌａ２ＣｕＯｙを使用しようとした場合、超伝
導層からＳｒイオン等が拡散してしまうと、それが僅か
な量でもトンネルバリア層の特性が金属的なものになっ
てしまい殆ど使用出来なくなる。又、トンネルバリア層
にＮｄ２ＣｕＯｙを使用する場合、Ｎｄ２ＣｕＯｙの格
子定数（ａ）が約３．９６オングストロームであるのに
対し、超伝導体であるＬａ２−ｘＭｘＣｕＯｙやＬａ２
−ｘＳｒｘＣａＣｕ２Ｏｙの格子定数（ａ）は３．７８
〜３．８２オングストロームでありその差が４〜５％と
大きく、エピタキシャルに結晶成長させるには内部応力
が大きくなり、その結果結晶に欠陥が入り素子として機
能しなくなってしまう。従って本発明の目的は、超伝導
体として主にＬａ２−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ
、Ｂａ）やＬａ２−ｘＳｒｘＣａＣｕ２Ｏｙを利用しよ
うとした場合のトンネルバリア層やバッファ層、基板等
に有用な金属酸化物材料を提供することにある。[Problem to be solved by the invention] L as a superconductor
a2-xMxCuOy (M=Ca, Sr, Ba) or La
When trying to use 2-xSrxCaCu2Oy etc., the semiconductor La2CuO is used as the tunnel barrier layer.
Candidates include y, Nd2CuOy, and the like. However, when trying to use La2CuOy, if Sr ions or the like diffuse from the superconducting layer, even a small amount of them will cause the properties of the tunnel barrier layer to become metallic, making it almost unusable. Furthermore, when Nd2CuOy is used for the tunnel barrier layer, the lattice constant (a) of Nd2CuOy is approximately 3.96 angstroms, whereas superconductors such as La2-xMxCuOy and La2
The lattice constant (a) of -xSrxCaCu2Oy is 3.78
~3.82 angstroms, and the difference is as large as 4 to 5%, and internal stress becomes large for epitaxial crystal growth, resulting in defects in the crystal and the device no longer functions. Therefore, the object of the present invention is to mainly use La2-xMxCuOy (M=Ca, Sr
, Ba) and La2-xSrxCaCu2Oy are useful for tunnel barrier layers, buffer layers, substrates, etc.
【０００５】[0005]
【課題を解決する為の手段】上記の目的は以下の本発明
によって達成される。即ち、本発明は、組成比がＬａａ
ＬｎｂＳｒｃＣｕ２Ｏｄと表される金属酸化物材料にお
いて、２．７＜ａ＋ｂ＋ｃ＜３．３、０．６＜ａ＜１．
０、０．６＜ｂ＜１．２、０．８＜ｃ＜１．６、４＜ｄ
＜８であり、且つＬｎがＹ、Ｈｏ、Ｄｙの元素のいずれ
かであることを特徴とする金属酸化物材料である。Means for Solving the Problems The above objects are achieved by the following invention. That is, in the present invention, the composition ratio is Laa
In the metal oxide material expressed as LnbSrcCu2Od, 2.7<a+b+c<3.3, 0.6<a<1.
0, 0.6<b<1.2, 0.8<c<1.6, 4<d
<8, and Ln is one of Y, Ho, and Dy elements.
【０００６】[0006]
【作用】本発明で用いている元素はＬａ、Ｓｒ、Ｃｕ、
ＯとＬｎ（Ｄｙ、Ｈｏ、Ｙ）であり、超伝導体であるＬ
ａ２−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ、Ｂａ）やＬａ
２−ｘＳｒｘＣａＣｕ２Ｏｙの元素と組成比は違うもの
のほぼ同じである。このことは超伝導体からトンネルバ
リア層等へのイオンの拡散若しくは逆の拡散が特性にあ
まり影響を与えないことを意味している。又、本発明の
金属酸化物材料の結晶の格子定数（ａ）は３．７〜３．
９オングストロームであり、使用する超伝導体とほぼ同
じ格子定数を持っている。これは超伝導との界面の整合
性がよくなり素子として非常に有利になる。[Operation] The elements used in the present invention are La, Sr, Cu,
O and Ln (Dy, Ho, Y), which is a superconductor
a2-xMxCuOy (M=Ca, Sr, Ba) or La
Although the elements and composition ratios of 2-xSrxCaCu2Oy are different, they are almost the same. This means that the diffusion of ions from the superconductor into the tunnel barrier layer or the like, or the reverse diffusion, does not significantly affect the characteristics. Further, the lattice constant (a) of the crystal of the metal oxide material of the present invention is 3.7 to 3.
It is 9 angstroms thick and has almost the same lattice constant as the superconductor used. This improves the consistency of the interface with the superconductor, making it very advantageous as a device.
【０００７】[0007]
【好ましい実施態様】本発明の銅酸化物材料は前記組成
を有する限りいずれのものでもよいが、本発明において
好適な材料は、０．８＜ｂ＜１．１、１＜ｃ＜１．５で
あり且つＬｎ＝Ｄｙである金属酸化物材料である。又、
好適な材料として結晶格子が正方晶若しくは斜方晶であ
り、格子定数（ａ若しくはｂ）が３．７５オングストロ
ーム以上３．８３オングストローム以下であり、且つ格
子定数（ｃ）が１９．５オングストローム以上２０．５
オングストローム以下である前記の金属酸化物材料であ
る。上記本発明の銅酸化物材料を作成する方法としては
、いわゆるセラミックス材料で一般に使われている様な
原料粉末からの加熱による反応及び焼結法がいずれも本
発明において使用可能である。この様な方法の例は、Ｍ
ａｔｅｒｉａｌ Ｒｅｓｅａｒｃｈ Ｂｕｌｌｅｔｉｎ
第８巻７７７頁（１９７３年）、Ｓｏｌｉｄ Ｓｔ
ａｔｅ Ｃｏｍｍｕｎｉｃａｔｉｏｎ 第１７巻２７頁
（１９７５年）、Ｚｅｉｔｓｃｈｒｉｆｔ ｆｕｒ Ｐ
ｈｙｓｉｋ Ｂ 第６４巻１８９頁（１９８６年）、
Ｐｈｙｓｉｃａｌ Ｒｅｖｉｅｗ Ｌｅｔｔｅｒｓ 第
５８巻第９号９０８頁（１９８７年）等に示されており
、これらの方法は現在では定性的には極めて一般的な方
法として知られている。[Preferred Embodiment] The copper oxide material of the present invention may be any material as long as it has the above composition, but the preferred materials in the present invention are 0.8<b<1.1, 1<c<1.5 and Ln=Dy. or,
Preferred materials include those whose crystal lattice is tetragonal or orthorhombic, whose lattice constant (a or b) is from 3.75 angstroms to 3.83 angstroms, and whose lattice constant (c) is from 19.5 angstroms to 20 angstroms. .5
The metal oxide material has a thickness of angstroms or less. As a method for producing the copper oxide material of the present invention, any of the reaction and sintering methods using heating from a raw material powder, which are generally used in so-called ceramic materials, can be used in the present invention. An example of such a method is M
material Research Bulletin
Volume 8, page 777 (1973), Solid St
ate Communication Vol. 17, p. 27 (1975), Zeitschrift fur P.
hysik B Vol. 64, p. 189 (1986),
Physical Review Letters, Vol. 58, No. 9, p. 908 (1987), and these methods are now qualitatively known as extremely common methods.
【０００８】特に本発明を超伝導材料成膜用の基板とし
て用いる場合、原料粉末をフラックス等を用い高温で溶
解してから単結晶成長させる方法も本発明において有用
である。又、本発明をトンネルバリア層やバッファ層に
用いる場合、原料を含むターゲットを用いた高周波スパ
ッタリングやマグネトロンスパッタリング等のスパッタ
リング法、電子ビーム蒸着、ＭＢＥ法、その他の真空蒸
着法或いはクラスターイオンビーム法や原料にガスを使
うＣＶＤ法又はプラズマＣＶＤ法等を使って基板上若し
くは超伝導薄膜上に本発明の材料を薄膜状に形成するこ
とが出来る。この様にして得られた本発明の銅酸化物材
料は、液体窒素温度以下で超伝導転移や金属的振る舞い
をせず、半導体的特性を示す。特に液体ヘリウム温度で
は十分高い電気抵抗率を有しトンネルバリア層として有
用である。又、本発明で使用する原料は全て安価なもの
であり、原料コストは低く本発明の材料は安価に提供可
能である。又、本発明の材料は空気中において比較的安
定で劣化も少なく、更に原料に重金属等の毒性のあるも
のを使用していないので安全性が高い。Particularly when the present invention is used as a substrate for forming a superconducting material film, a method of melting raw material powder at high temperature using flux or the like and then growing a single crystal is also useful in the present invention. In addition, when the present invention is used for a tunnel barrier layer or a buffer layer, sputtering methods such as high frequency sputtering and magnetron sputtering using a target containing raw materials, electron beam evaporation, MBE method, other vacuum evaporation methods, cluster ion beam method, etc. The material of the present invention can be formed into a thin film on a substrate or a superconducting thin film using a CVD method or a plasma CVD method using gas as a raw material. The copper oxide material of the present invention thus obtained exhibits semiconducting properties without superconducting transition or metallic behavior below the liquid nitrogen temperature. In particular, it has a sufficiently high electrical resistivity at liquid helium temperatures and is useful as a tunnel barrier layer. Further, all the raw materials used in the present invention are inexpensive, and the cost of raw materials is low, and the material of the present invention can be provided at low cost. Furthermore, the material of the present invention is relatively stable in the air and has little deterioration, and is highly safe since it does not use toxic materials such as heavy metals as raw materials.
【０００９】[0009]
【実施例】次に実施例及び比較例を挙げて本発明を更に
具体的に説明する。実施例１〜９及び比較例１〜８原料
としてＬａ２Ｏ３、ＳｒＣＯ３、ＣｕＯ、Ｄｙ２Ｏ３、
Ｈｏ２Ｏ３、Ｙ２Ｏ３、Ｅｒ２Ｏ３、Ｇｄ２Ｏ３を用い
、これらを適当な組成比に坪量して乾式混合した。これ
らの混合物を夫々φ１０ｍｍ、厚み１ｍｍのペレット状
に加圧形成し、形成物を夫々アルミナボートの上で１，
０００〜１，１６０℃で大気中若しくは酸素中で反応及
び焼結させ、本発明及び比較例の銅酸化物を調製した。
以下の表１に実施例の組成比を示す。又、表２には比較
例の組成比を示す。ここで組成比はＥＰＭＡで測定した
ので、酸素の量に関しては２０％程度の誤差がある。[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1 to 9 and Comparative Examples 1 to 8 Raw materials include La2O3, SrCO3, CuO, Dy2O3,
Using Ho2O3, Y2O3, Er2O3, and Gd2O3, these were dry-mixed at an appropriate composition ratio in basis weight. These mixtures were pressurized into pellets with a diameter of 10 mm and a thickness of 1 mm, and the formed products were placed on an alumina boat for 1.
Copper oxides of the present invention and comparative examples were prepared by reacting and sintering at 000 to 1,160°C in air or oxygen. Table 1 below shows the composition ratios of Examples. Table 2 also shows the composition ratios of comparative examples. Here, since the composition ratio was measured by EPMA, there is an error of about 20% regarding the amount of oxygen.
【００１０】図１には実施例１のＸ線回折パターンを示
す。この図から実施例１のサンプルはａ＝ｂ＝３．７９
オングストローム、ｃ＝１９．７オングストロームの格
子定数をもつ正方晶であることがわかる。他の実施例も
これとほぼ同じ回折パターンを示し、同様の構造を有し
ていることが分かる。このことから本発明の材料は超伝
導体であるＬａ２−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ、
Ｂａ）やＬａ２−ｘＳｒｘＣａＣｕ２Ｏｙの格子定数（
ａ）とほぼ同じ格子定数（ａ）を持ち、トンネルバリア
層やバッファ層或いは基板として有効であることがわか
る。FIG. 1 shows the X-ray diffraction pattern of Example 1. From this figure, the sample of Example 1 is a=b=3.79
It can be seen that it is a tetragonal crystal with a lattice constant of c=19.7 angstroms. It can be seen that the other examples also show almost the same diffraction pattern as this, and have similar structures. From this, the material of the present invention is a superconductor La2-xMxCuOy (M=Ca, Sr,
Ba) and the lattice constant of La2-xSrxCaCu2Oy (
It can be seen that it has almost the same lattice constant (a) as a) and is effective as a tunnel barrier layer, buffer layer, or substrate.
【００１１】又、図２にはこのサンプルの電気抵抗率の
温度依存性のグラフを示す。低温で抵抗率が上昇し、半
導体的性質を持っていることがわかる。他の実施例のサ
ンプルもこれとほぼ同様な半導体的性質を示す。このこ
とにより本発明の材料はトンネルバリア層としても有効
であることがわかる。又、表１の中で実施例１、２及び
３がＸ線回折及び電気抵抗率の測定の結果から特に特性
が良いことがわかった。又、２の比較例の１〜６では、
Ｌａ２−ｘＳｒｘＣｕＯ４、Ｄｙ２Ｏ３、Ｅｒ２Ｏ３、
Ｇｄ２Ｏ３等の不純物が多く析出し特性の悪いものであ
った。FIG. 2 shows a graph of the temperature dependence of the electrical resistivity of this sample. It can be seen that the resistivity increases at low temperatures, indicating that it has semiconducting properties. Samples of other examples also exhibit substantially similar semiconductor properties. This shows that the material of the present invention is also effective as a tunnel barrier layer. Further, in Table 1, Examples 1, 2, and 3 were found to have particularly good characteristics from the results of X-ray diffraction and electrical resistivity measurements. In addition, in Comparative Examples 1 to 6 of 2,
La2-xSrxCuO4, Dy2O3, Er2O3,
Many impurities such as Gd2O3 were precipitated and the properties were poor.
【００１２】0012
【表１】[Table 1]
【００１３】[0013]
【表２】[Table 2]
【００１４】[0014]
【効果】以上説明した様に、本発明により以下の効果が
得られる。
（１）新規な組成比を有し、格子定数（ａ）が超伝導体
であるＬａ２−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ、Ｂａ
）やＬａ２−ｘＳｒｘＣａＣｕ２Ｏｙの格子定数（ａ）
とほぼ同じであり、電気的特性が半導体である銅酸化物
材料が得られた。このことから本発明の材料はトンネル
バリア層として特に効果がある。
（２）本発明の材料に用いられる元素はＬａ、Ｓｒ、Ｃ
ｕ、Ｙ、Ｄｙ、Ｈｏ、Ｏであり、超伝導体であるＬａ２
−ｘＭｘＣｕＯｙ（Ｍ＝Ｃａ、Ｓｒ、Ｂａ）やＬａ２−
ｘＳｒｘＣａＣｕ２Ｏｙに用いられる元素とほぼ同じで
あり、両者を接合した場合の元素の拡散の影響が極めて
少ない。[Effects] As explained above, the following effects can be obtained by the present invention. (1) La2-xMxCuOy (M=Ca, Sr, Ba
) and the lattice constant (a) of La2-xSrxCaCu2Oy
A copper oxide material with almost the same electrical characteristics as a semiconductor was obtained. For this reason, the material of the present invention is particularly effective as a tunnel barrier layer. (2) Elements used in the material of the present invention are La, Sr, and C.
u, Y, Dy, Ho, O, and superconductor La2
-xMxCuOy (M=Ca, Sr, Ba) and La2-
The elements are almost the same as those used in xSrxCaCu2Oy, and the influence of element diffusion when both are bonded is extremely small.
【００１５】[0015]
【図１】実施例１のＬａ０．７５Ｄｙ０．９５Ｓｒ１．
３Ｃｕ２Ｏ６のｘ線回折パターン。この時のＸ線はＣｕ
Ｋα線を用いた。FIG. 1: La0.75Dy0.95Sr1 of Example 1.
X-ray diffraction pattern of 3Cu2O6. The X-ray at this time is Cu
Kα rays were used.
【図２】実施例１のＬａ０．７５Ｄｙ０．９５Ｓｒ１．
３Ｃｕ２Ｏ６の電気抵抗率の温度依存性のグラフ。FIG. 2 La0.75Dy0.95Sr1 of Example 1.
Graph of temperature dependence of electrical resistivity of 3Cu2O6.
Claims (3)
ｄと表される金属酸化物材料において、２．７＜ａ＋ｂ
＋ｃ＜３．３、０．６＜ａ＜１．０、０．６＜ｂ＜１．
２、０．８＜ｃ＜１．６、４＜ｄ＜８であり、且つＬｎ
がＹ、Ｈｏ、Ｄｙの元素のいずれかであることを特徴と
する金属酸化物材料。[Claim 1] Composition ratio is LaaLnbSrcCu2O
In the metal oxide material represented by d, 2.7<a+b
+c<3.3, 0.6<a<1.0, 0.6<b<1.
2, 0.8<c<1.6, 4<d<8, and Ln
A metal oxide material characterized in that is any of the elements Y, Ho, and Dy.
であり、且つＬｎ＝Ｄｙである請求項１に記載の金属酸
化物材料。[Claim 2] 0.8<b<1.1, 1<c<1.5
The metal oxide material according to claim 1, wherein Ln=Dy.
り、格子定数（ａ若しくはｂ）が３．７５オングストロ
ーム以上３．８３オングストローム以下であり、且つ格
子定数（ｃ）が１９．５オングストローム以上２０．５
オングストローム以下である請求項１に記載の金属酸化
物材料。3. The crystal lattice is tetragonal or orthorhombic, the lattice constant (a or b) is 3.75 angstroms or more and 3.83 angstroms or less, and the lattice constant (c) is 19.5 angstroms or more. 20.5
The metal oxide material according to claim 1, which has a thickness of angstroms or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3077143A JPH04292415A (en) | 1991-03-18 | 1991-03-18 | Metal oxide material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3077143A JPH04292415A (en) | 1991-03-18 | 1991-03-18 | Metal oxide material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04292415A true JPH04292415A (en) | 1992-10-16 |
Family
ID=13625579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3077143A Pending JPH04292415A (en) | 1991-03-18 | 1991-03-18 | Metal oxide material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04292415A (en) |
-
1991
- 1991-03-18 JP JP3077143A patent/JPH04292415A/en active Pending
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