Abstract: The present invention relates to an aircraft transparency including an electroconductive metal oxide coating over a rigid plastic substrate, and a polyurethane protective liner over the metal oxide coating, and more specifically to the use of a primer for adhering the metal oxide coating to the substrate and/or a primer for adhering the polyurethane protective liner to the metal oxide coating. The metal oxide primer includes a carbonate diol-based crosslinked polyurethane. The polyurethane primer is selected from the group consisting of a crosslinked copolymer of acrylic acid and substituted acrylates such as 2-ethylhexylacrylate; a crosslinked copolymer of cyanoethylacrylate and acrylic acid; and a crosslinked terpolymer of 2-ethylhexylacrylate, cyanoethylacrylate and acrylic acid.

Abstract: A thin film of a perovskite-type transparent potassium niobate formed on an amorphous substrate. The thin film of a perovskite-type potassium niobate has excellent transparency, can be (110) oriented, and can be used for optical devices, such as an optical waveguide, a second harmonic generating device, and an optical switching device. The amorphous substrate is a glass substrate or a composite amorphous substrate comprising an amorphous layer which contains at least one element selected from the group consisting of alkaline earth metal elements, rare earth elements, Bi, Pb, Nb, Co, Ni, and W.

Abstract: A high-temperature superconducting thin film of compound oxide selected from the group consisting of:Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Ho.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Lu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Sm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Nd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Gd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Eu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Er.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Dy.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Tm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Yb.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, La.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,(La, Sr).sub.2 CuO.sub.4-x,which is deposited on a substrate of MgO or SrTiO.sub.3, with the outer surface of the high-temperature superconducting thin film being covered with a protective crystalline film of SrTiO.sub.3.

Abstract: A close a-axis orientating film having a smooth surface and excellent ferroelectric characteristics is manufactured at a low temperature with preferable reproducibility to apply ferroelectric Bi.sub.4 Ti.sub.3 O.sub.12 to development of various kinds of devices such as a ferroelectric non-volatile memory, a pyroelectric sensor, etc. A ferroelectric Bi.sub.4 Ti.sub.3 O.sub.12 thin film is formed on a substrate through a titanium oxide buffer layer so that closeness and surface smoothness of the Bi.sub.4 Ti.sub.3 O.sub.12 thin film manufactured on the titanium oxide buffer layer can be improved.

Abstract: A process and structure wherein a film comprised of a perovskite or a spinel is built epitaxially upon a surface, such as an alkaline earth oxide surface, involves the epitaxial build up of alternating constituent metal oxide planes of the perovskite or spinel. The first layer of metal oxide built upon the surface includes a metal element which provides a small cation in the crystalline structure of the perovskite or spinel, and the second layer of metal oxide built upon the surface includes a metal element which provides a large cation in the crystalline structure of the perovskite or spinel. The layering sequence involved in the film build up reduces problems which would otherwise result from the interfacial electrostatics at the first atomic layers, and these oxides can be stabilized as commensurate thin films at a unit cell thickness or grown with high crystal quality to thicknesses of 0.5-0.7 .mu.m for optical device applications.

Abstract: An SOI substrate comprises a buried silicon oxide layer formed directly under an active silicon layer, and a layer containing phosphorus therein formed under the buried silicon oxide layer. The layer containing phosphorus therein acts as the getter layer, so that an effective gettering of heavy metals can be obtained in a wide temperature range from a low temperature region to a high temperature region. In addition, since the silicon oxide layer exists between the active layer and the getter layer, the diffusion of the phosphorus into the active layer is effectively prevented, and therefore, the phosphorus scarely diffuses to the active layer, so that the device manufactured is subjected to almost no adverse influence of the diffusion of the phosphorus.

Abstract: A bonded wafer 10 has a silicon device layer 20 bonded to a layer of semi-insulating material 14, preferably a mobility degraded silicon such as polycrystaline silicon. Layer 14 is thick enough and substrate 16 is conductive enough to reduce resistive losses when devices in layer 20 are operated at frequencies above 0.1 Ghz. Substrate 16 is conductive enough and semi-insulating material 14 is resistive enough to prevent cross-talk among devices in layer 20.

Abstract: Boron-aluminum nitride B.sub.x Al.sub.1-x N.sub.y (0.001.ltoreq.x.ltoreq.0.70, 0.85.ltoreq.y.ltoreq.1.05) films having wurtzite type structure are proposed. The material has higher hardness, higher sound velocity and wider band gap than hexagonal aluminum nitride (AlN).

Abstract: Blades for use in combusion turbine engines are formed from a single crystal aluminum garnet body--desirably a rare earth aluminum garnet body--having an epitaxial surface layer of a second aluminum garnet having a lattice constant larger than that of the body garnet so as to provide a compressive strain, to thereby strengthen the blade.

Abstract: A transparent conductive film of a zinc oxide type containing gallium and silicon, which contains silicon in an amount of from 0.01 to 1.5 mol % in terms of SiO.sub.2.

Abstract: A novel raised polycide fusible link structure is described. This structure enables a highly reliable laser-cutting process to be used in which the fuse can be easily and totally severed over a wide range of laser energy levels. The primary feature of the structure is that the fusible link is located on a pedestal that raises it above the surface of the main body of the integrated circuit, thereby providing a measure of thermal isolation for the fuse when it is irradiated by the laser. An efficient process for manufacturing the structure is also described.

Abstract: A new polycrystalline silicon film which has been crystallized using a polycrystalline silicon-germanium (poly-Si.sub.1-x Ge.sub.x) capping film to "seed" crystallization of an amorphous silicon film on an upper surface of a substrate. The polycrystalline silicon film has no nucleation sites and a greater number of grain boundaries in the region near the polycrystalline silicon upper surface than in the region near the polycrystalline silicon and substrate upper surface interface. This indicates that crystallization and crystal growth occurred from the polycrystalline silicon upper surface and proceeded in a direction towards the substrate upper surface.

Abstract: A thin film semiconductor device including an insulating substrate; and a structure provided on the insulating substrate and including a silicon layer containing hydrogen diffused therein and a silicon nitride layer. The insulating substrate is formed of an insulating material having a thermal expansion coefficient of 2.6.times.10.sup.-6 deg.sup.-1 or more or having a distortion point of 850.degree. C. or lower.

Abstract: A method for producing a single crystal, which comprises (1) placing a metal layer as a pattern at a desired position on the surface of a single crystal substrate, (2) etching the surface of the single crystal substrate around the pattern, and (3) in a raw material gas atmosphere containing an element or elements constituting the single crystal, taking the element or elements in the metal layer at the pattern and permitting a needle-like single crystal to grow perpendicularly.

Abstract: An epitaxial wafer capable of removing impurities and oxide layers thereon having a high dielectric strength is disclosed. A substrate wafer 1 in which laser-scattering centers have a density of higher than 5.times.10.sup.6 /cm.sup.3 is provided. An epitaxial layer 3 is formed by epitaxial growth on a completely clean surface of the substrate. The surface of the epitaxial layer consists of a non-defect layer which is provided for device active regions. Moreover, a high density of laser-scattering centers are distributed near the interface of the epitaxial layer and the substrate wafer and the interior of the substrate, thus providing for a wafer capable of removing impurities.

Abstract: A process for preparing a semiconductor substrate comprises a step of porousifying a silicon monocrystalline substrate to form a porous layer, a step of making a silicon monocrystalline thin film to epitaxially grow on a surface of the porous layer, a step of oxidizing the surface of the epitaxial growth layer, a step of forming a deposited film on the oxidized surface, thereby obtaining a first substrate, a step of closely contacting the deposited film of the first substrate to a second substrate, a step of heat treating the closely contacted substrates and a step of selectively etching the porous layer.

Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.

Abstract: An oriented conductive thin film useful as a thin film electrode or a thin film resistor is disclosed, comprising an epitaxial or oriented ABO.sub.3 type oxide (e.g., BaPbO.sub.3) conductive thin film which is obtained by coating a single crystal oxide substrate or a single crystal semiconductor substrate with a solution of a metal oxide precursor comprising an organometallic compound, thermally decomposing the coating layer, followed by annealing. An epitaxial or oriented ABO.sub.3 type ferroelectric thin film may further be provided on the conductive thin film.

Abstract: Optoelectric article includes a substrate made of an optoelectric single crystal and a film of a single crystal of lithium niobate formed on the substrate by a liquid phase epitaxial process, wherein a ratio of lithium/niobium of a composition of the film of the lithium niobate single crystal falls in a range of 48.6/51.4 to 49.5 to 50.5 or 50.5/49.5 to 52.3/47.7.

Abstract: Fused alumina particles are covered with a coating of aluminum titanate which is formed by applying a Ti-containing compound to the surface of the fused alumina particles and firing the same to cause a reaction between the Ti-containing compound and the alumina.

Abstract: A non-magnetic single crystal of Mn--Zn ferrite obtained by a solid phase reaction process including the steps of contacting a seed single crystal ferrite with a polycrystal crystal ferrite and producing the single crystal by growing the single crystal in a direction from the seed single crystal toward the polycrystal under heating. The single crystal of Mn--Zn ferrite has a composition defined by points A, B, C, D and E in a three-phase diagram of Fe.sub.2 O.sub.3 --MnO--ZnO, in which:A: Fe.sub.2 O.sub.3 40 mol %, MnO 10 mol %, ZnO 50 mol %;B: Fe.sub.2 O.sub.3 40 mol %, MnO 35 mol %, ZnO 25 mol %;C: Fe.sub.2 O.sub.3 70 mol %, MnO 5 mol %, ZnO 25 mol %;D: Fe.sub.2 O.sub.3 70 mol %, MnO 2 mol %, ZnO 28 mol %; andE: Fe.sub.2 O.sub.3 48 mol %, MnO 2 mol %, ZnO 50 mol %.

Abstract: A surface magnetostatic wave device includes an Fe-containing garnet single crystal film grown on a gadolinium gallium garnet substrate. The crystallographic plane azimuth of the gadolinium gallium garnet substrate can be one of a (110) plane, a (100) plane, and a (211) plane. The device achieves both a reduced saturation magnetization and a reduced anisotropic magnetic field to thereby minimize the lowest frequency in the propagation band.

Abstract: Siloxene and siloxene derivatives are compatible with silicon and may be generated as epitaxial layer on a silicon monocrystal. This permits the production of novel and advantageous electroluminescent devices, such as displays, image converters, optoelectric integrated circuits. Siloxene and siloxene derivatives may also be advantageously employed in lasers as laser-active material and in fluorescent lamps or tubes as luminescent material.

Abstract: In one form of the invention, a method is disclosed for fabricating a semiconductor-on-insulator structure comprising the steps of: forming an insulator layer 22; forming a layer 24 comprising boron (B) on the insulator layer 22; and forming a semiconductor layer 26 on the layer 24 comprising B.

Abstract: A ceramic composite material consisting of single crystal .alpha.-Al.sub.2 O.sub.3 and single crystal Y.sub.3 Al.sub.5 O.sub.12 is provided. This composite material has high mechanical strength and creep behavior particularly at high temperatures.

Abstract: When a zinc oxide piezoelectric crystal film is epitaxially grown on an R-plane sapphire substrate by sputtering, a target containing not more than 4.5 percent by weight of Cu with respect to the total content of Zn and Cu is employed so that the zinc oxide piezoelectric film contains Cu. Thus, it is possible to obtain a zinc oxide piezoelectric crystal film having excellent orientation.

Abstract: A composite body, especially for use as a cutting tool, for the lining of combustion chambers or for movable parts intended to have low wear which has a substrate of hard metal, steel, cermet or nickel or cobalt alloy. The substrate is provided with at least one fine-crystalline alpha-Al.sub.2 O.sub.3 layer deposited by plasma activated CVD at 400.degree. to 750.degree. C. With plasma activation by pulsed direct voltage with the substrate connected as the cathode.

Abstract: An orientative ferroelectric thin film has such a structure that an epitaxial or orientative buffer layer having a double layer structure constituted by two layers is formed on a semiconductor single crystal (100) substrate, and an epitaxial or orientative perovskite ABO.sub.3 type ferroelectric thin film is further formed on the buffer layer. The epitaxial or orientative buffer layer has a structure in which a perovskite ABO.sub.3 type thin film is formed on an MgO thin film. Also, an orientative ferroelectric thin film has such a structure that an opitaxial MgO buffer layer is formed on a single crystal Si (100) substrate, and an epitaxial or orientative perovskite ABO.sub.3 type ferroelectric thin film is formed on the buffer layer.

Abstract: High quality epitaxial layers can be grown on a multi-layer substrate which has a crystalline pseudomorphic layer with an exposed surface used for the epitaxial growth. The pseudomorphic layer of the substrate has a thickness at or below the pseudomorphic limit so it will be deformed as stress forces are developed during epitaxial growth of heteroepitaxial structures. A plastically deformable layer is bonded to the pseudomorphic layer, This plastically deformable layer is made of material that plastically flows at epitaxial growth temperatures.

Abstract: In a layer structure oxide in crystallite form having a composition of the formula: AMO.sub.2 wherein A is Li or Na and M is Co, Ni, Fe or Cr, at least one additive element Z which is Bi, Pb or B is present in the form of an oxide on the surface of crystallites or between crystallites. Atomic ratio Z/M is from 0.0001 to 0.1. Since the crystallites have an increased size, the layer structure oxide has improved properties and is suitable for use as a positive electrode material of a secondary cell.

Abstract: The invention relates to new films for applying to a substrate and to methods for producing them.A composition, for use in preparing a film, (preferably an epitactic film) comprising a solid solution of KNbO.sub.3 and KTaO.sub.3 forming a product of formula IK.sub.1-y M.sub.y Ta.sub.1-x Nb.sub.x O.sub.3 (I)in which M is a monovalent metal ion other than K.sup.+ (hereinafter defined as the dopant);y=0.02 to 0.20 andx=0.05 to 0.95.

Abstract: A novel structure has, on a substrate a nonlinear optical thin film having a high .chi..sup.(3) value provided wherein metal fine particles are uniformly dispersed in a ferroelectric or highly dielectric matrix and heat treated whereby the metal fine particles and matrix are improved in crystallinity. The excitation wavelength can be substantially changed by a choice of the heat treating conditions. The crystallinity of the metal fine particles and matrix and .chi..sup.(3) value are improved by selecting a proper substrate or changing the heat treating procedure and conditions. The thin film is further improved in nonlinear optical properties, typically .chi..sup.(3) and .chi..sup.(3) /.alpha. values by using a perovskite type compound ABO.sub.3 having a specific A/B ratio as the matrix material and controlling film deposition conditions for improving the crystallinity of the matrix.

Abstract: A multilayer structure has an a nonlinear optical film epitaxially grown on an underlying buffer layer of substantially lower refractive index. The buffer layer itself is epitaxially grown on a single crystal substrate with an intermediate epitaxial electrode.

Abstract: The present invention provides for the fabrication of single layer semimetal/semiconductor heterostructures and multilayer semimetal/semiconductor structures. Each semimetal/semiconductor layer fabricated in accordance with the present invention has compatible crystal symmetry across the heterojunction between a semimetal and a semiconductor. A single layer semimetal/semiconductor structure is fabricated by growing a rhombohedral semimetal in a [111] direction on a substrate material having a (111) orientation, and then growing a zincblende semiconductor in a [111] direction on the semimetal. A multilayer semimetal/semiconductor structure may be grown from the single layer semimetal/semiconductor structure by growing an additional rhombohedral semimetal layer in a [111] direction on the preceding semiconductor grown, then growing an additional zincblende semiconductor layer in a [111] direction on the additional semimetal layer, and then repeating this process as many times as desired.

Abstract: In order to grow a GaAs.sub.1-x P.sub.x fixed-composition layer of excellent quality, which has a predetermined composition x, over a GaAs or GaP single crystal substrate, a varied-composition layer is formed between the substrate and the fixed-composition layer. The varied-composition layer comprises at least two varied-composition layer portions and at least one fixed-composition layer portion with a predetermined thickness that is formed between the varied-composition layer portions, whereby dislocations caused by lattice mismatch with the GaP substrate are settled in the varied-composition layer portions and recovered in the fixed-composition layer portion between the varied-composition layer portions, thereby minimizing the dislocations, and thus making it possible to obtain a GaAs.sub.1-x P.sub.x layer of excellent crystal quality, which has a predetermined composition x.

Abstract: This invention relates to a method for forming, and constructs of, bonded composites of single crystal materials. The method comprises the steps of optically contacting the surfaces of the single crystal materials selected to form an assembly, bonding the surfaces by gradually heating the assembly to a temperature and for a duration sufficient to diffusion bond the surfaces, and cooling the bonded assembly at a rate which avoids thermal shock and allows the removal of stress by annealing. No bonding agents are necessary. Moreover, since the bonding temperature does not have to reach the substances' melting or fusing temperature, minimal distortion and displacement of the surfaces results.

Abstract: A superconducting thin film of compound oxide material deposited on a substrate, comprising a plurality of a-axis or b-axis oriented unit layers (2) and a plurality of c-axis oriented unit layers (1), each unit layer (1, 2) being made of the compound oxide material and being laminated alternately one over another on the substrate (3).

Abstract: A high frequency superconducting device structure is disclosed which comprises an alkaline earth fluoride substrate with a magnesium oxide lower buffer layer on the alkaline earth substrate and an upper buffer layer epitaxial template layer on the magnesium oxide layer for providing a template for epitaxial growth of a high temperature superconducting film on the upper buffer layer, providing reduced dielectric and conducting losses at high frequencies. The disclosed structure may be incorporated into a multi-chip module (MCM) for providing very high speed interconnections.

Abstract: c-axis oriented microwave quality HTSC films are deposited onto single crystals of gadolinium gallium garnet (GGG) using pulsed laser deposition (PLD) with conditions of 85 mTorr of oxygen partial pressure, a block temperature of 730.degree. C., a substrate surface temperature of 790.degree. C. and a laser fluence of 1 to 2 Joules/cm.sub.2 at the target, a laser repetition rate of 10 Hz and a target to substrate distance of 7 cm and in which the a and b lattice parameters of the GGG exhibit a mismatch of less than 2.5 percent with the a and b lattice parameters of the HTSC.

Abstract: A functional thin film member is composed of an insulating substrate; a first single crystal thin film layer which contains at least one atom component of Si or Ge, formed on the insulating substrate; an intermediate layer with a cubic crystal system and a lattice constant difference of 15% or less with respect to the lattice constant of the single crystal thin film layer, formed on said single crystal thin film layer; and a second single crystal thin film layer of an oxide formed on the intermediate layer. The first single crystal thin film layer may include crystal orientations suitable for the properties of functional members to be provided above the single crystal thin film layer on an identical plane of the surface of the single crystal thin film layer, and the intermediate layer may be formed in at least one portion of the single crystal thin film layer, corresponding to any of the crystal orientations.

Abstract: A novel nonlinear optical thin film having a high .chi..sup.(3) value is provided wherein metal fine particles are uniformly dispersed in a ferroelectric or highly dielectric matrix and heat treated whereby the metal fine particles and matrix are improved in crystallinity. The excitation wavelength can be substantially changed by a choice of the heat treating conditions.The crystallinity of the metal fine particles and matrix and .chi..sup.(3) value are improved by selecting a substrate used or changing the heat treating procedure and heat treating conditions. By forming a portion having a lower content of metal fine particles in a surface portion on an upper and/or lower side of the matrix, the excitation wavelength can be substantially changed and precisely adjusted.

Abstract: A superconducting thin film of a compound oxide represented by YBa.sub.2 Cu.sub.3 O.sub.y in which "y" is a number of 6<y<8 and deposited on a substrate, characterized in that a buffer layer of a compound oxide represented by Y.sub.2 BaCuO.sub.x in which "x" is a number of 4<x<6 is interposed between the superconducting thin film and the substrate.

Abstract: A Bi-Sr-Ca-Cu-O system superconducting thin film formed on a substrate comprising [110] single crystals of an ABO.sub.3 type oxide having a perovskite structure, in which a (119) face is selectively grown relative to a substrate surface. The film is formed on the substrate by chemical vapor deposition process. A method of manufacturing a BiSrCaCuO system superconducting film in which an a-axis is oriented preferentially relative to the surface of a substrate comprising MgO (100) single crystals, wherein the chemical composition ratio (Sr+Ca+Cu)/Bi of the BiSrCaCuO system superconducting film is made not less than 3.5. A Bi-Sr-Ca-Cu-O system superconducting thin film formed on a substrate comprising MgO [110] single crystals, in which a (110) face is selectively grown to the substrate surface. The film is formed on the substrate by a chemical vapor deposition process.

Abstract: The present invention relates to a composite material. This material comprises at least one layer A of III-V compound and one epitaxial layer B on said layer of III-V compounds, the epitaxial layer corresponding to the empirical formula REPc, where RE is chosen from the group comprising the rare earths (scandium, yttrium, preferably lanthanum, lanthanides, and their mixtures); and where Pc is chosen from the elements of column V of the periodic table of the elements and their mixtures, and, when Pc contains arsenic, the compound REPc is at least a ternary compound.Application is to the electronics industry.

Abstract: A superconducting system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

Abstract: A superconducting thick film circuit board or thick film superconductor obtained by forming a rod-like crystal superconducting composite layer comprising a superconductor made of a compound of M-Ba-Cu-O, M being Y and/or a lanthanide element, and a composite of Ag and Pt on a stabilized zirconia substrate has a high Jc value and good superconducting properties.

Abstract: Semiconductor crystals are formed by applying a semiconductor crystal forming treatment on a substrate having a free surface on which a deposition surface (S.sub.NDS) with a small nucleation density and a deposition surface (S.sub.NDL) with metal having a sufficiently small area for crystal growth only from a single nucleus and having a greater nucleation density (ND.sub.L) than the nucleation density (ND.sub.S) of the deposition surface (S.sub.NDS) are arranged adjacent to each other, thereby growing a semiconductor single crystal from the single nucleus.

Abstract: A cubic perovskite crystal structure is disclosed satisfying the unit cell formula:R.sub.0.33+z A.sub.0.67 C.sub.1-y O.sub.3-xwhereR, A and C represent rare earth, alkaline earth and copper atoms, respectively, capable of forming a superconductive R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure;x is 0.67 to 1.0;y is up to 0.2; andz is up to 0.1.The crystal structure can be used to form superconductive superlattices and weak links for Josephson junction devices. The crystal structure can be produced by laser ablation deposition at a temperature below that required for the formation of a superconductive R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure. The crystal structure can be used as a substrate for the subsequent deposition of an R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure.

Abstract: Novel crystalline .alpha. (silicon nitride-like)-carbon nitride and .beta. (silicon nitride-like)-carbon nitride are formed by sputtering carbon in the presence of a nitrogen atmosphere onto a single crystal germanium or silicon, respectively, substrate.

Abstract: A superconductive system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.