Abstract: Disclosed is a method of forming a thin junction film including a first thin oxide flilm presenting a superconductivity and second thin oxide film presenting an insulator properties or possibly semiconductive properties with an improved production efficiency as well as improved film quality and characteristics. Employed are first and second targets each having substantially the same chemical composition excepting oxygen content. The first target is sputtered at a target cathode voltage of minus 100 V by the use of voltage derived from an external D.C. voltage source, thereby forming a first thin oxide film. Subsequently, the target is changed over to the second target while changing the target cathode voltage into self-bias voltage of minus 50 V without any change of the other film formation conditions.

Abstract: A high temperature superconductor lead assembly for reduces the heat leak into a cryocooled magnet system includes a superconductor and a first lead connector bonded to a first end of the superconductor. The lead connector includes an electrically insulating, thermally conductive ceramic mount for attachment to a mechanical cryocooler for cooling the connector. The superconductor is in the form of a stack of ribbons. The superconductor is attached to an electrically and thermally insulating support. A cryocooled magnet system includes a mechanical cryocooler having a warm end and a cold end, a superconductor magnet maintained at a temperature of the cold end of the cryocooler, two superconductor leads, and two current carrying leads for supplying power to the superconductor leads.

Abstract: A method for fabricating a superconducting device with a substrate, a first oxide superconductor thin film, a barrier layer, a diffusion layer, and a second oxide superconductor thin film. The first oxide superconductor thin film with a very thin thickness is formed on the principal surface of the substrate. The barrier layer and the diffusion source layer are formed on a portion of the first oxide superconductor thin film. The second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film until the barrier and diffusion source layers are embedded in the second oxide superconductor thin film, so that a material of the diffusion source layer is diffused into the second oxide superconductor thin film.

Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.

Abstract: A process for controlling crystalline orientation of an oxide superconductive film includes a first-heat-treatment step, and a second-heat-treatment step. In the first-heat-treatment step, an oxide superconductive film is heated and held in non-oxidizing atmosphere. Accordingly, partial oxygen deficiency is caused in the oxide superconductive film. In the second-heat-treatment step, the oxide superconductive film is heated and held in oxygen-rich atmosphere. Consequently, oxygen is re-introduced into the oxide superconductive film. Thus, crystalline orientation of the oxide superconductive film is altered. The process enables to readily form not only an "a"-axis-oriented oxide superconductive film but also a "b"-axis-oriented oxide superconductive film.

Abstract: A thin film which is substantially free of measurable surface defects due to second-phase inclusions is disclosed. The film is composed of multilayered strata of a first metal oxide interspersed with single molecular layers of a second metal oxide, where the second metal oxide is effective to absorb second-phase defects which form in the first oxide layers.

Abstract: The invention provides a method for preparing a layered structure made up of a plurality of thin films composed of different compositions, in which the method involves using a reactive co-evaporation technique to deposit a first thin film on a substrate using a first set of evaporation sources, and then depositing another thin film of a different composition on the first thin film, using a second set of evaporation sources that has no evaporation sources common with the first set of evaporation sources. In the method, the first thin film is deposited in a first deposition sub-chamber and the second thin film is deposited in a second deposition subchamber, both of which are part of a single vacuum chamber.

Abstract: Fine epitaxial patterns of yttrium barium copper oxide on a strontium titanate substrate are provided by using a silicon nitride mask to define the pattern to be formed. A thin film of yttrium barium copper oxide is placed on the silicon nitride mask and exposed portions of strontium titanate substrate. Where the yttrium barium copper oxide is in contact with the silicon nitride mask, it is nonepitaxial in crystal structure. Where the yttrium barium copper oxide contacts the strontium titanate substrate in the openings, it is epitaxial in structure forming fine patterns that become superconducting below the critical transition temperature. A channel can be formed in the strontium titanate substrate. The epitaxial yttrium barium copper oxide pattern is formed in this channel to minimize possible exposure to the silicon nitride mask.

Abstract: The present invention relates to a polycrystalline thin film deposit acting as a substrate material composed of grains of a cubic structure in which the intergranular misorientation, defined as the orientation difference between the a-axes (or b-axes) of the neighboring grains, is less than 30 degrees. Such a substrate base is produced by depositing a target material on a base material by sputtering while irradiating the substrate base with ion beams at an oblique angle to the base. The preferred range of the oblique angle is between 40 to 60 degrees. Examples are presented of application of such textured polycrystalline substrate base for the production of superconducting oxide thin layer of outstanding superconducting properties.

Abstract: Described is a process for manufacturing thin films by periodically depositing (DEP) a number of block layers consisting of different base materials on a substrate (multilayer deposition), wherein the thickness of the layers (LT) is restricted to one to 20 monolayers and deposition as well as crystallization of the thin film is completed at approximately constant temperature without performing a separate annealing step. The method can be used to produce thin films of high-T.sub.c -superconductors. It allows a better control of the crystal growth of ternary or higher compounds with comparatively large unit cells.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: A process for depositing successively a plurality of thin films on a bottom superconductor layer made of oxide superconductor deposited on a substrate in a single chamber under a condition, the bottom superconductor layer is heated in ultra-high vacuum at a temperature which is lower than the oxygen-trap temperature (T.sub.trap) at which oxygen enter into the oxide superconductor but higher than a temperature which is lower by 100.degree. C. than the oxygen-trap temperature (T.sub.trap -100.degree. C.) and then the first thin film is deposited thereon.

Abstract: A process for preparing an YBCO oxide thin film which has a crystalline, clean and smooth surface on a substrate. The process is conducted by using an apparatus comprising a vacuum chamber in which an oxidizing gas of O.sub.2 including O.sub.3 can be supplied near the substrate so that pressure around the substrate can be increased while maintaining high vacuum near an evaporation source and K cell evaporation sources arranged in the vacuum chamber wherein the substrate is heated, molecular beam of constituent atoms of the oxide excluding oxygen are supplied from the K cell evaporation sources, and a chilled oxidizing gas is locally supplied to the vicinity of the substrate.

Abstract: A process for removing contaminants from a surface of a thin film of oxide superconductor deposited on a substrate. The thin film of oxide superconductor is heat-treated in ultra-high vacuum at a temperature which is within a range of -100.degree. C. to +100.degree. C. of the temperature at which oxygen enter into the oxide superconductor.The process is used for removing photo-resist from a surface of thin film of oxide superconductor and for producing a layered structure containing at least one thin film of oxide superconductor such as Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x having a contaminated surface. On the cleaned surface, another thin film of oxide superconductor or non-superconductor is deposited. The resulting structure of layered thin films is used for fabricating superconducting transistor, Josephson junctions, superconducting circuits or the like.

Abstract: A method of preparing a substrate with a view to depositing a thin layer of a superconductive material thereon, wherein an operation is performed of depositing on the substrate an intermediate material having the property of having a crystal lattice constant that is a function of the percentage of a doping element, the depositing operation being initiated with a concentration of the doping element such that the lattice constant of the intermediate material is equal to or as close as possible to the lattice constant of the substrate, the proportion of the doping element being continuously varied during the depositing operation to a proportion of the doping element such that the lattice constant of the intermediate material is equal to or as close as possible to the lattice constant of the superconductive material.

Abstract: A perovskite type superconductor film having a high content, almost a single phase, of the high Tc phase is formed by the steps of: depositing at least one first film of a first material (e.g., a composite oxide of Bi-Sr-Ca-Cu-O system or Tl-Ba-Ca-Cu-O system) constituting a perovskite type superconductor over a substrate; depositing at least one second film of a second material containing an oxide or element (Bi.sub.2 O.sub.3, Tl.sub.2 O.sub.3, PbO.sub.x, etc., particularly PbO.sub.x) having a vapor pressure of more than 10.sup.-4 Pa at 800.degree. C. at least as a main component over the substrate; to thereby form a stack of the first and second films; and heat treating the stack of the first and second films to form the perovskite type superconductor film on the substrate. Further, preferred compositions of the as-deposited films or stack are determined.

Abstract: This invention relates to a process of forming multilayered thallium-containing superconducting composites, wherein a first thallium-containing superconducting layer, an intermediate thallium-containing oxide layer and a second thallium-containing superconducting layer are successively deposited on a substrate by a vapor phase process by controlling the heating temperature, pressure of oxidizing gas and thallium vapor pressure during post-deposition annealing of the superconducting films.

Abstract: For manufacturing a superconducting device having a tunnel junction formed of an extremely thin insulator layer sandwiched between a pair of oxide superconductor thin films, a first superconducting layer of oxide superconductor thin film is formed on a substrate, and a MgO thin film is deposited on the first superconducting layer at a substrate temperature of not higher than 200.degree. C. The MgO thin film is heat-treated so that crystallinity of the deposited MgO thin film is improved, and thereafter, a second superconducting layer of oxide superconductor thin film is formed on the MgO thin film.

Abstract: A substrate free single crystal pyroelectric film particularly suited for use in rapid thermal response sensors is made from a single crystal substrate by a method including the steps of:(A) etching a pattern into the substrate;(B) epitaxially growing a highly oriented superconducting material into the etched pattern to fill the etched pattern,(C) epitaxially growing a highly oriented crystalline film of a pyroelectric material over the entire surface of the substrate, and(D) dissolving away the highly oriented superconducting material.

Abstract: For manufacturing a superconducting device, a first oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. A second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film, using the gate electrode as a mask, so that first and second superconducting regions having a relatively thick thickness are formed at opposite sides of the gate electrode, electrically isolated from the gate electrode. A source electrode and a drain electrode is formed on the first and second oxide superconducting regions. The superconducting device thus formed can functions as a super-FET.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: The present invention is directed to a method for growing a superconductive film on a superconductive substrate in order to produce a bulk single crystal. According to a preferred embodiment, an oxide superconductive film of a material which is the same or similar to the substrate material is epitaxially grown at a temperature between 450.degree. C. and 800.degree. C. so that the film and substrate have the same lattice orientations. According to the present invention, problems associated with conventional films having non-superconductor substrates (e.g., MgO and SrTiO.sub.3) are avoided.

Abstract: The present invention comprises a high quality, epitaxial thallium-based HTS thin film on MgO and other substrates and methods of providing the same. The present invention is achieved using a nucleation layer which provides a template for subsequent growth. Specifically, YBCO and/or YBCO analog films (films having growth characteristics and physical structures analogous to YBCO) are used as nucleation layer(s) on MgO and other substrates to enable the growth of epitaxial thallium-based HTS films.

Abstract: A superconducting device comprises a substrate, a non-superconducting layer formed in a principal surface of said substrate, an extremely thin superconducting channel formed of an oxide superconductor thin film on the non-superconducting layer. A superconducting source region and a superconducting drain region of a relatively thick thickness are formed of the oxide superconductor at the both sides of the superconducting channel separated from each other but electrically connected through the superconducting channel, so that a superconducting current can flow through the superconducting channel between the superconducting source region and the superconducting drain region.

Abstract: Disclosed is a method of manufacturing a thin film of an oxide superconductor represented by formula Sr.sub.1-x Nd.sub.x CuO.sub.2 on a substrate. The oxide superconductor has a tetragonal crystal structure, the lattice constant in a-axis falling within a range of between 0.385 nm and 0.410 nm, and the lattice constant in c-axis being an integer number of times as much as a level falling within a range of between 0.310 nm and 0.350 nm. The method includes the steps of forming by epitaxial growth a film of a crystal having lattice constants close to those of the crystal of said oxide superconductor on a substrate, and forming a thin film of the oxide superconductor of a tetragonal crystal structure represented by general formula (I) by a thin film-forming technique.

Abstract: A method of manufacturing a superconducting device involves forming a thin film on the surface of a substrate, forming a superconducting gate electrode on a portion of the thin film, etching the portions of the thin film using the gate electrode as a mask thereby providing a superconducting channel under the gate, forming a step portion on the superconducting channel and under the gate, converting the oxide portion of the step portion into a gate insulation portion by heating the substrate in a vacuum, forming a second oxide superconducting film on the exposed surface of the channel so that superconducting source and drain electrodes are formed on each side of the gate such that the drain and source have a thickness greater than that of the channel and are electrically isolated from the gate electrode.

Abstract: A method of fabricating a thin-film Hg-containing oxide superconductor is disclosed, which comprises forming a thin film on a substrate, said thin film containing mercury, an alkaline earth element, and copper as main components thereof; and subjecting said substrate with the thin film to a heat treatment in an oxygen-containing atmosphere at an oxygen partial pressure of 1/500 to 1/10 atm, to convert said thin film to the thin-film superconductor.

Abstract: A multi-featured control system which improves the manufacturing capability of the thin-film semiconductor growth process. This system improves repeatability and accuracy of the process, reduces the manpower requirements to operate MBE, and improves the MBE environment for scientific investigation. This system has three levels of feedback control. The first level improves the precision and tracking of the process variables, flux, and substrate temperature. The second level comprises an expert system that uses sensors to monitor the status of the product in order to tailor the process plan in real time so that the exact qualities desired are achieved. The third level features a continuously evolving neural network model of the process which is used to recommend the recipe and command inputs to achieve a desired goal. The third level is particularly useful during the development process for new materials.

Abstract: Superconducting transition metal oxide films are provided which exhibit very high onsets of superconductivity and superconductivity at temperatures in excess of 40.degree. K. These films are produced by vapor deposition processes using pure metal sources for the metals in the superconducting compositions, where the metals include multi-valent nonmagnetic transition metals, rare earth elements and/or rare earth-like elements and alkaline earth elements. The substrate is exposed to oxygen during vapor deposition, and, after formation of the film, there is at least one annealing step in an oxygen ambient and slow cooling over several hours to room temperature. The substrates chosen are not critical as long as they are not adversely reactive with the superconducting oxide film. Transition metals include Cu, Ni, Ti and V, while the rare earth-like elements include Y, Sc and La. The alkaline earth elements include Ca, Ba and Sr.

Abstract: A superconducting thin oxide film is formed by the steps of mixing a gas of the organometal compound of the alkali earth metal, a gas of at least one organometal compound of the element of the group IIIa and/or a halogenide thereof, and a gas of at least one organometal compound of a transition metal and/or a halogenide thereof, with an inert gas, to produce a gas mixture; mixing an oxygen-containing gas to said gas mixture to produce a gas mixture having a predetermined oxygen partial pressure; and thermally decomposing said gas mixture having the predetermined oxygen partial pressure on a substrate to form a thin film of a complex oxide on said substrate.

Abstract: A method for forming a patterned oxide superconductor thin film on a substrate comprises steps of forming a metal or semi-metal layer on a portion of the substrate, on which the oxide superconductor thin film will be formed, forming a layer of a material including silicon on a portion of the substrate, on which an insulating layer will be formed, removing the metal or semi-metal layer and depositing an oxide superconductor thin film over the substrate.

Abstract: A method for making layered structures of artificial high T.sub.c superconductor compounds by which on top of a seed crystal having a lattice structure matching the lattice structure of the superconductor compound to be made, oxide layers of all constituent components are epitaxially grown in a predetermined sequence so as to create a sandwich structure not found in natural crystals. The epitaxial deposition of the constituent components is performed in a reaction chamber having evaporation facilities, inlets for metal-organic gases, and inlets for background gases including oxygen.

Abstract: A method of preparing a superconducting oxide by combining the metallic elements of the oxide to form an alloy, followed by oxidation of the alloy to form the oxide. Superconducting oxide-metal composites are prepared in which a noble metal phase intimately mixed with the oxide phase results in improved mechanical properties. The superconducting oxides and oxide-metal composites are provided in a variety of useful forms.

Abstract: In-situ process are provided for 1) depositing on a substrate a crystalline thin film of a high temperature superconducting oxide by exposing the back surface of the substrate, i.e., the surface of the substrate opposite the surface on which the thin film is deposited, to radiation from a direct radiant heat source, thereby heating the substrate to the desired growth temperature, and maintaining the radiation and thereby the desired growth temperature during the deposition of the thin film, and 2) depositing a crystalline thin film of high temperature superconducting oxides onto both the front and back surfaces of a substrate.

Abstract: A method for depositing a thin film of a material on an oxide thin film having a perovskite type crystal structure formed on a substrate comprising steps of depositing a seed layer of a single crystal of the material having an extremely thin thickness at a relatively high substrate temperature on the oxide thin film having a perovskite type crystal structure and depositing a thin film of the material on the seed layer at a lower substrate temperature.

Abstract: For manufacturing a superconducting device, a first c-axis orientated oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is formed on a portion of the first oxide superconductor thin film. An a-axis orientated oxide superconductor thin film is grown, using the gate electrode as a mask, so that second and third superconducting regions having a relatively thick thickness are formed at both sides of the gate electrode, electrically isolated from the gate electrode. The superconducting device thus formed can functions as a super-FET.

Abstract: A thin film device comprising a substrate and an oxide superconductor film formed thereon, wherein said oxide superconductor film comprises atomic monolayers each composed of at least one kind of element of the oxide superconductor, which are deposited substantially in a vertical direction to the substrate so that the pereodicy of the lattice structure of the oxide superconductor is substantially maintained, and at an intermediate portion of the oxide superconductor film, at least a part of the atoms of the oxide superconductor is substituted by other element in the lattice structure of the oxide superconductor to form a non-superconductor interlayer, and the pereodicy of the lattice structure of the oxide superconductor film is substantially maintained across the interface between the oxide superconductor and said non-superconductor interlayer.

Abstract: A structure having a silicon substrate with an epitaxially grown magnesium oxide layer on a surface onto which is epitaxially grown, either directly or on an intermediary layer, a layer of high temperature superconducting material.

Abstract: An oxide superconductor thin film of Y.sub.1.+-..alpha. Ba.sub.2.+-..beta. Cu.sub.3.+-..gamma. O.sub.7-.delta. with a smooth surface having a low density of particles being generated without decreasing superconductivity is produced by the steps of applying a pulsed laser beam to the target formed of an oxide material having an apparent density of 95% or more, substantially composed of Y.sub.1.+-..alpha. Ba.sub.2.+-..beta. Cu.sub.3.+-..gamma. O.sub.7-.delta., which is obtained from a molded body of an amorphous powder by subjecting it to partial melting, followed by gradual cooling, depositing and accumulating an irradiated and evaporated oxide material of the target on a substrate.

Abstract: A method for producing a thin oxide superconducting film possessing high crystallinity and excellent quality and a novel single crystal as a substrate allowing easy formation of an epitaxial film of high quality usable for the method are provided. The method for the production of the thin oxide superconducting film is characterized by using as a substrate a single crystal of SrLaGaO.sub.4 which is a high-melting oxide and effecting epitaxial growth of a thin oxide superconducting film on the substrate. The single crystal used as a substrate is an oxide single crystal possessing a crystal structure of the K.sub.2 NiF.sub.4 type and having a composition of Sr.sub.1-X La.sub.1-Y Ga.sub.1-Z O.sub.4-W (wherein X, Y, Z, and W fall in the following respective ranges; -0.1<X<0.1, -0.1<Y<0.1, -0.1<Z<0.1, and -0.4<W<0.4).

Abstract: A method for preparing a thin film formed of an oxide superconductor on a substrate by emitting molecular beams of constituent elements of the oxide superconductor to the substrate under high vacuum, wherein at first a molecular beam of one of the constituent elements of the oxide superconductor, of which an oxide thin film can be deposited so as to have a smooth surface, is emitted so as to form the oxide thin film of one or two unit cells. And then, all the molecular beams of constituent elements of the oxide superconductor are emitted to the oxide thin film so as to form the oxide superconductor thin film.

Abstract: An in-situ process for preparing thin films which contain relatively volatile and involatile oxides is disclosed, in particular, crystalline thin films of oxides of conductors, superconductors or ferroelectric materials, wherein separate sources of the relatively volatile and involatile oxides during depositon of the thin film are employed.

Abstract: Provided herein is a method of efficiently preparing a thin film having a higher critical temperature as to an oxide superconducting material containing Tl. A thin film of an oxide containing Tl is formed and then heat treated at a temperature of about 850.degree. to 950.degree. C. for a short time, and thereafter further heat treated at a temperature, which is lower than the preceding heat treatment temperature, of at least about 750.degree. C. for a long time. The thin film is heat treated in an atmosphere having an oxygen partial pressure of not more than about 0.1 atm. In formation of a Tl superconducting thin film, on the other hand, a 1212 phase layer is reacted with an amorphous Ca--Cu--O layer to form a 1223 phase layer, or a layer containing volatile metal elements (Tl, Bi and Pb, for example) and oxygen is reacted with another layer containing other elements than the volatile metal elements to form a superconducting film having a high critical temperature.

Abstract: A thin film superconductor assembly is disclosed along with a method of fabricating same. The assembly comprises a self-supporting substrate defining at least a portion of a containment for a flow of cryogenic fluid, a dielectric layer adherent to a surface of the substrate, a thin film superconductor adherent to the dielectric layer and a moisture and oxygen impervious electrically insulating coating covering the thin film superconductor. A method of forming such thin film superconductor assembly, wherein the dielectric layer consists essentially of aluminum nitride, comprises growing the aluminum nitride dielectric layer integrally on the surface of the substrate.

Abstract: A method for manufacturing an oxide superconductor thin film is disclosed, which comprises the steps of: (1) preparing a substrate; depositing an oxide superconductor thin film on said substrate by directing a beam containing constituent elements of an oxide superconductor to said substrate; and supplying excited oxygen to or near a thin film deposition site on said substrate during the deposition of said thin film, wherein said beam is selected from the group consisting of an ion beam, neutral particle beam, molecular beam, cluster beam and cluster ion beam, and wherein said excited oxygen is produced by means of generating discharge in an oxygen gas or oxygen-containing gas or by irradiating an oxygen gas or oxygen-containing gas with a beam.

Abstract: A process for forming a single crystal superconducting LnA.sub.2 Cu.sub.3 O.sub.7-x film, wherein Ln is at least one rare earth element and A is at least one alkaline earth element, is disclosed, which comprises simultaneously evaporating Ln, A and Cu in an atomic ratio of about 1:2:3 from discrete evaporation sources of Ln, A and Cu onto a heated substrate in a vacuum vessel while blowing an oxygen gas onto the substrate to form an oxygen-containing atmosphere, thereby forming the single crystal superconducting film on the substrate.

Abstract: An evaporation method of producing a new high Tc superconducting material using fullerene molecules as artificial pinning sites for any magnetic flux that may enter the material.

Abstract: This invention relates to strontium titanate, hereinafter referred to as SrTiO.sub.3, films of the type produced by chemical vapor deposition (CVD) that are oriented so that the film's (100) face is parallel to the surface plane of the substrate. Such structures of this type, generally allow the SrTiO.sub.3 film to be deposited such that a high density capacitor or a buffer layer for a superconductor can be created.

Abstract: A method for applying a metal film barrier layer between a substrate and a superconductor coating or over a superconductivity coating using chemical vapor deposition in which low vapor pressure reactants are used, is disclosed, which comprises the steps of providing a substrate and a quantity of metal-bearing reagent and one or more reagents, placing the substrate within the furnace, introducing the metal-bearing reagent by a powder feeder means and then the reagents at different times into and reacting them in the furnace, resulting in the deposition first of a coating of metal onto the substrate and then of a coating consisting essentially of the superconducting reactant components onto the metal film; said reagents generally chosen to yield the group of oxide superconductors.

Abstract: The present invention provides a method of manufacturing a high quality oxide superconductor film capable of controlling the film-forming rate and the film composition easily and forming the superconductor film safely and economically, over a wide region and homogeneously, wherein each of elements of R in which R represents one or more of elements selected from the group consisting of Y and lanthanide series rare earth elements, Ba and Cu is vapor deposited in the state of metal on a substrate under a high vacuum of lower than 10.sup.-8 Torr by a vacuum vapor deposition process to form a precursor comprising an amorphous metal and the precursor is oxidized and crystallized by applying a heat treatment without taking out the same into the atmospheric air.