Abstract: An embodiment relates to a cladded composite comprising a cladding layer of a bulk metallic glass and a substrate; wherein the bulk metallic glass comprises approximately 0% crystallinity, approximately 0% porosity, less than 50 MPa thermal stress, approximately 0% distortion, approximately 0 inch heat affected zone, approximately 0% dilution, and a strength of about 2,000-3,500 MPa.

Abstract: The present invention relates to a coating for high-temperature uses with tribological stress. The coating comprises a multi-layer system and a top lubricant layer, the top lubricant layer containing molybdenum as a main component.

Abstract: An electromagnetic radiation shielding device includes a first ply having a No. 1 surface and a No. 2 surface and a second ply having a No. 3 surface and a No. 4 surface. The No. 2 surface of the first ply faces the No. 3 surface of the second ply. A first coating having three or more metallic layers is provided over at least a portion of one of the surfaces, such as over at least a portion of the No. 2 surface. A second coating having three or more metallic layers is provided over at least a portion of one or more of the other surfaces, such as over at least a portion of the No. 3 surface.

Abstract: The invention provides a composite material, which includes a titanium alloy substrate and a metallic glass layer. The metallic glass layer is disposed on the titanium alloy substrate. The thickness of the metallic glass layer is 50 nm-200 nm, in which in comparison with the titanium alloy substrate, the fatigue life of the composite material of the invention is increased by 5-17 times.

Abstract: A reflection metal diffraction grating has a high diffraction efficiency for diffracting femtosecond mode laser pulses, and includes a substrate with a set of lines having a pitch A. The substrate is made of metal or covered with a metal layer, and the grating includes a thin film of dielectric material having a thickness, the dielectric film covering the metal surface of the lines of the grating, the grating being suitable for receiving a pulsed electromagnetic lightwave in a femtosecond mode. The thickness of the dielectric thin film is lower than 50 nm, and is suitable for reducing by a third order factor at least the maximum of the square of the electric field of the electromagnetic lightwave on the metal surface and in the metal layer of the substrate as compared to the square of the electric field at the surface of a metal grating not having a dielectric thin film.

Abstract: An improved electrical connector for use with a glazing is disclosed. The glazing preferably comprises a ply of glazing material having a first electrically conductive component mounted thereon, and a second electrically conductive component, joined to the first by a lead-free solder. The second component has a thickness t and comprises first and second connector feet linked by a bridge portion, the bridge portion being at a height h above each of the connector feet. T and/or h are chosen to minimise the occurrence of stress faults in the glass in the region of the solder. Preferably, the glazing is an automotive glazing.

Abstract: A multi-layer thin film stack, particularly suitable as a component of a solar cell, is deposited on a transparent dielectric substrate. The multi-layer film stack comprises a transparent electrically conductive metal oxide layer deposited over the dielectric substrate, the conductive metal oxide layer having a refractive index less than 2.0, a light transmittance optimizing interlayer having a refractive index between 2.3 and 3.5, deposited over the electrically conductive metal oxide layer, and a silicon layer having a refractive index of at least 4.5 deposited over the light transmittance optimizing interlayer. The film stack can be deposited by any suitable method, but deposition of each of these layers by atmospheric chemical vapor deposition is preferred.

Abstract: A coating process and system suitable for use on components subjected to high temperatures. The coating system includes an overlay coating of predominantly B2 phase rhodium aluminide (RhAl) intermetallic compound containing about 25 to about 90 atomic percent rhodium, about 10 to about 60 atomic percent aluminum, optionally up to a combined total of about 25 atomic percent of one or more platinum group metals chosen from the group consisting of platinum, palladium, ruthenium, and iridium, and up to about 20 atomic percent of the base metal and alloying constituents of the substrate. The RhAl intermetallic coating may serve as an environmental coating, a diffusion barrier layer for an overlying environmental coating, or both, with or without an outer ceramic coating.

Abstract: A first ceramic substrate includes a substrate (2) and a glaze layer (3), wherein the glaze layer has a surface having an Ra of 0.02 ?m or less and a Ry of 0.25 ?m or less. A second ceramic substrate is formed by subjecting a glass layer (24) formed on a surface of a substrate (2) to heating-and-pressurizing treatment, thereby forming a glaze layer (3) on the substrate (2), and planarization-polishing the surface of the glaze layer. A third ceramic substrate includes a substrate (2), a glaze layer (3) containing substantially no pores formed on the substrate (2) and the surface thereof being planarization-polished, and a wiring pattern (21), wherein at least one first end of the wiring pattern is exposed to the glaze layer (3) surface of the substrate (1), and at least one second end is exposed to another surface of the substrate (1).

Abstract: A ceramic substrate for a thin film electronic component, a production method thereof, and a thin film electronic component using the ceramic substrate A first substrate (1) includes a dense glass-ceramic mixed layer (33) containing glass in its surface portion. A second substrate is prepared such that a glass layer (32) formed on a surface of a substrate base portion (2) is subjected to a heat-pressure treatment so as to form or rather partly change the glass portion (32) into a dense glass-ceramic mixed layer (33) in which glass is dispersed into a surface portion of the substrate base portion (2). A surface of the dense glass-ceramic mixed layer (33) is then subjected to grinding or rather polishing to flatten and expose a surface of the dense glass-ceramic mixed layer (32). A third substrate includes a substrate base portion (2) having a dense glass-ceramic mixed layer (33) containing glass on a surface portion in one face side, and a wiring pattern (21) formed inside the substrate base portion (2).

Abstract: A resin composition comprising an inorganic material with a thermal conductivity of 10 W/mK or higher at a temperature of 20° C. and an aromatic polyester is provided. The aromatic polyester may have structural units derived from (I) 2-hydroxy-6-naphthoic acid, (II) a compound selected from hydroquinone, 4,4?-dihydroxybiphenyl and 2,6-dihydroxynaphthalene, (III) naphthalenedicarboxylic acid and (IV) a compound selected from terephthalic acid, isophthalic acid and phthalic acid.

Abstract: A monolayer or multilayer film has a single layer or multiple layers of silica containing fluorine. An optical element has the forgoing film laid on a surface of a substrate. A concentration of the fluorine in the layer or layers of silica is not less than 0.1 mol % (referably, not less than 1 mol %) nor more than 10 mol %.

Abstract: Steel sheet for porcelain enameling having excellent workability yet capable of providing an enamel layer having excellent adhesion with the steel sheet on direct-on enameling once and still free of black specks defects, a method for producing the same, as well as a porcelain enamel product and the method for producing the same are provided, in which low carbon Al-killed steel sheet, high oxygen steel sheet, Ti-added steel sheet, Nb-added steel sheet, Ti—Nb-added steel sheet or B-added steel sheet is used. A steel sheet for porcelain enameling is produced by applying Ni—Mo alloy plating to the low carbon Al-killed steel sheet, high oxygen steel sheet, Ti-added steel sheet, Nb-added steel sheet, Ti—Nb-added steel sheet or B-added steel sheet having specified components and composition ratio, and after performing heat treatment thereto to control the content of Ni, Mo, and Fe that are present on the surface of the steel sheet in a predetermined range, porcelain enamel is applied and fired.

Abstract: In this method of manufacturing a device, when discharging the liquid drops upon the substrate, a bit map made up from a plurality of pixels against which liquid drops are discharged is established upon the substrate. When establishing the pixels, when the interval of the discharge nozzles of the liquid drop discharge head 1 is taken as “a”, and the size in the Y axis direction of the pixels is taken as by, the pixels are established so that the condition by=a/n is satisfied, where n is a positive integer.

Abstract: A multi-layered structure, and method for producing same, which may include at least one glass layer anodically bonded to an intermediate layer. The intermediate layer may function as an anodic bonding layer, an etch stop layer, and/or a hard mask layer. A template may be formed of the multi-layered structure by forming a desired pattern of openings therein by way of, for example, etching. Such a template may, for example, be used in the alignment and adherence of spacer structures to an electrode plate during the fabrication of flat panel displays. When used in this context, the construction of such a template results in more precise control of the patterning and sizing of the holes formed therein which thereby allows for more precise placement of spacer structures as well as the use of spacer structures exhibiting relatively higher aspect ratios during the fabrication of flat panel displays.

Abstract: A functional film includes a transition layer having a first constituent having SiO as a dielectric material and at least one second constituent selected from aluminum (Al), silver (Ag), silicon (Si), germanium (Ge), yttrium (Y), zinc (Zn), zirconium (Zr), tungsten (W) and tantalum (Ta). The first and second constituents have corresponding gradual content gradients according to a thickness of the functional film.

Abstract: This invention relates to thermoplastic interlayers for laminated safety glass with superior vacuum de-airing at elevated temperatures and superior tacking and edge sealing properties. The sheeting has surface pattern on at least one of the surfaces characterized by flat surfaces with substantially uninterrupted channels for air flow in at least two intersecting directions. The channels allow for rapid de-airing while the area roughness parameter ratio ARp/ARt in the range of 0.52 to 0.62, ARt being less than 32 &mgr;m. and area kurtosis less than 2.5, allow for ease of tacking of the interlayer onto glass and edge sealing after de-airing has been completed. Said surface pattern may also be superimposed onto a pattern which is generated by melt fracture or other means on at least one side to enhance de-airing and aid edge sealing.

Abstract: A sealing structure for an organic light emitting device display. The sealing structure comprises a metal film overlying a dielectric film. The sealing structure has low moisture and oxygen permeability. At least one of the metal layers may react with moisture or oxygen to seal off pin holes. A net low stress sealing structure may be formed by combining tensile and compressive films. The sealing structure may be etched to create openings for connection to outside circuitry. The innovative sealing structure minimizes moisture leakage and vertical shorts between diode cathode and anode.

Abstract: A composite steel sheet including a steel base member; an undercoat having opposed surfaces and a thickness of 10-750 .mu.m obtained by spraying one or more spraying materials selected from metals, non-oxide ceramics, oxide ceramics and cermets onto the steel base member. The undercoat has an oxide layer of not less then 0.5 .mu.m in thickness on one of the opposed surfaces positioned away from said steel base member. A fired topcoat is formed on the oxide layer of the undercoat from a vitreous coating having a linear expansion coefficient of 4-11.times.10.sup.-6 /.degree.C.

Abstract: High magnesium-content magnesium aluminosilicate glasses are used to form green tape compositions that are fired stepwise, i.e., first to about 500.degree. C. to remove organic materials, then to a temperature 10-30.degree. C. above the glass transition temperature for a time sufficient to nucleate the glass, and finally to a higher temperature near but below the softening temperature to complete crystallization of the glass. The resultant glass-ceramic may include substantial amounts of the forsterite crystalline phase. Multilayer ceramic printed circuit boards are made that are useful for high frequency, microwave applications. The fired high magnesium oxide content glasses have low dielectric constant and low dissipation loss factors, and they have a thermal coefficient of expansion that is compatible with metal or ceramic support substrates that impart mechanical strength to the printed circuit boards and that are thermally conductive. The boards are compatible with gallium arsenide devices.

Abstract: The present invention provides a joined product of heat-resisting alloys, comprising heat-resisting alloy sheets or foils optionally having an oxide film on their surfaces, said heat-resisting alloy sheets or foils being joined to each other at their surfaces facing each other with an composite having a melting point in the range of from 800.degree. to 1400.degree. C. The joined product of heat-resisting alloys is produced by putting the above-described composite oxide on a heat-resisting alloy in a sheet or foil form at its portion to be joined, putting another heat-resisting alloy in a sheet or foil form and heating the resulting assembly at a temperature of 9/10 or more of the melting point of the composite oxide.

Abstract: In a magnetoresistive read transducer, a material which is inert with respect to the soft film magnetic biasing layer is formed at the surface of the substrate prior to soft film deposition. In a preferred embodiment of the present invention, a substrate surface layer of metal such as Cr or Ta is used. These metals have high resistivity due to partial oxidation when deposited on the substrate to reduce shunting of sensing current through the magnetoresistive layer, and further acts as a barrier to protect the soft film from substrate interface contamination. The surface layer also acts as a seed layer to set the soft film magnetization orientation in a well-defined direction therefore reducing magnetic instability.

Abstract: A fine, hard particulate is distributed within a fused coating on a substrate. The distributed, fine, hard particulate function as crack arresters, so that a propagating crack is actually stopped upon encounter with the hard particle, and enhance nucleation during the coating formation, so that finer grain size is achieved within the coating, which in effect decreases the crack length in the coating.

Abstract: Painted metal sheet pretreated with a composite coating including an insoluble, inorganic inner layer and an organic outer layer. The inorganic layer is formed by rinsing the sheet with an alkaline solution containing at least 0.005M of at least one of a dissolved silicate or a dissolved aluminate. The sheet is dried to form an inorganic layer having a thickness of at least 2 .ANG.. The inorganically coated sheet then is rinsed with a solution containing at least 0.1 vol.-% of a hydrolyzed silane and at least 0.02 vol.-% of a hydrolyzed crosslinking agent. The silane treated sheet is dried to form a siloxane layer having an average thickness at least 5 .ANG.. After being painted, the siloxane layer forms an adherent bond between the paint and the metal substrate. The metal preferably is a chromium alloyed steel and may be etched prior to being rinsed with the alkaline solution to remove chromium oxide to further enhance the paint adhesion.

Abstract: An alloy of 3 to 9 weight percent boron with the balance molybdenum for use as a thermal spray coating for articles intended to be exposed to molten zinc.

Abstract: A glass composition and method of preparation utilizes a mixture consisting of phosphorus oxide within the range of about 40 to 49 molar percent, lead oxide within the range of about 10 to 25 molar percent, iron oxide within the range of about 10 to 17 molar percent and an alkali oxide within the range of about 23 to 30 molar percent. The glass resulting from the melting and subsequent solidifying of the mixture possesses a high degree of durability and a coefficient of thermal expansion as high as that of any of a number of metals. Such features render this glass highly desirable in glass-to-metal seal applications.

Abstract: Improved via-filling compositions for producing conductive vias in circuitized ceramic substrates, particularly multilayer substrates, without cracking and/or loss of hermetic sealing. The via-filling compositions comprise pastes containing a mixture of (a) ceramic and/or glass spheres of substantially- uniform diameter between about 0.5 and 6 .mu.m, (b) conductive metal particles or spheres having a maximum dimension or diameter between about 1/3 and 1/4 of the diameter of the ceramic and/or glass spheres, and (c) a binder vehicle. The formed conductive via bodies comprise a uniform conductive skeletal network of sintered metal particles densely packed within a uniform matrix of the co-sintered ceramic and/or glass spheres, which matrix is hermetically fused and integrated with ceramic layers forming the wall of the via in the ceramic circuit substrate.

Abstract: A structural component of metal is protected against titanium fires that can be caused by flying and burning titanium droplets, e.g. in a propulsion unit. The protection against titanium fires of metal structural components is provided by a surface coating made of ceramic fibers embedded in a matrix material of a high temperature lacquer having dispersed therein aluminum powder as a filler material. The high temperature resistant lacquer is formed of silicates as a vehicle in which the aluminum powder is dispersed.

Abstract: In accordance with the present invention, there are provided information recording media having a substrate and thereon a recording layer and a metallic layer, wherein the metallic layer is composed of an aluminum alloy containing (i) titanium and (ii) at least one metal selected from among chromium, niobium and magnesium. The information recording media thus provided are excellent in corrosion resistance and small in dependence of the recording power on linear velocity.

Abstract: An aqueous coating composition is provided for thermoplastic films comprising(i) from 1 to 10 weight percent based upon the total weight of the coating composition, of a sulfonated copolyester consisting essentially of the polyester condensation product of the following monomers or their polyester-forming equivalents:(A) about 65 to 95 mole percent of isophthalic acid;(B) about 0 to 30 mole percent of at least one aliphatic dicarboxylic acid of the formula HOOC(CH.sub.2)--.sub.n COOH, wherein n ranges from about 1-11;(C) about 5 to about 15 mole percent of at least one sulfomonomer containing an alkali metal sulfonate group attached to a dicarboxylic aromatic nucleus; and(D) stoichiometric quantities of about 100 mole percent of at least one copolymerizable aliphatic or cycloaliphatic alkylene glycol having about from 2 to 11 carbon atoms,(ii) from 0.

Abstract: A paste of a glazing composition is coated on the entire surface of a ceramic substrate having a metallized metal portion, and the paste-coated ceramic substrate is sintered in a reducing atmosphere, and a glazing layer is formed on the entire surface of the metallized metal portion by utilizing the repellency of the melt of the glazing composition to the metallized metal portion. A glazing composition comprising SiO.sub.2, B.sub.2 O.sub.3, BaO, Al.sub.2 O.sub.3 and an alkali metal oxide or a glazing composition comprising SiO.sub.2, BaO, Al.sub.2 O.sub.3, CaO and MgO or SrO is used. An acrylic resin syrup, especially an isobutyl methacrylate resin syrup, is used as a binder of a coating paste for forming a glazing layer.

Abstract: A multiple layer high transmittance, low emissivity coated article is disclosed with improved chemical resistance as a result of a protective overcoat of titanium oxide.

Abstract: A multiple layer high transmittance, low emissivity coated article is disclosed with improved chemical resistance as a result of a protective overcoat of titanium oxide.

Abstract: A novel low temperature vacuum seal and method of making same for joining a nonmetallic element, such as an optical port, to a metallic element is described which comprises first and second thin metallic layers applied to the nonmetallic element to provide substantial adhesion and solderability to the nonmetallic element, and a third metallic layer applied to the metallic element to provide solderability to the metallic element, the nonmetallic and metallic elements being joined by a layer of low temperature solder interfacing their respective solder surfaces. A further thin metallic layer may be applied to the nonmetallic element to provide substantial wetability to the solderable second layer.

Abstract: A process for the partial hot dipping of a long steel strip is disclosed which comprises forming an oxidation-inhibiting film, oxygen-impermeable and thermally stable in a hot-dipping bath, which film is produced by the chemical reaction of an iron content in the steel strip with an oxidation inhibiting film-forming agent, such as an inorganic phosphoric acid compound, on a predetermined area of the steel strip surface, forming, as required, an intermediate layer comprising an inorganic binder, such as water glass, on the resulting film, forming a carbon-containing, plateing-stopping film as a top coat on the intermediate layer, and hot dipping the steel strip.

Abstract: An infrared radiation reflecting substrate, having deposited thereon a first layer formed from a metal or an alloy, and a second layer deposited on the first layer and consisting of a solar radiation absorbing amorphous material, such as amorphous carbon. The substrate can be formed from an infrared radiation reflecting layer deposited on a primary substrate.

Abstract: The surface of a metal article which is exposed to the atmosphere and abrasion during normal use of the article is protected from scratches and/or corrosion during such use by a thin transparent abrasion-resistant film of an inert non-metallic material such as SiO.sub.2, SiC, Si.sub.3 N.sub.4, TiO.sub.2, MgO, Al.sub.2 O.sub.3, Ta.sub.2 O.sub.5, Nb.sub.2 O.sub.5, GeO.sub.2, spinel and selected colorless glass compositions. The protective film is preferably deposited by RF-sputtering techniques and undesirable coloration of the article by optical interference effects from incident light rays is avoided by properly correlating the film thickness with the refractive index of the particular material used to form the film. The invention permits the use of thinner gold plating on such items as articles of expensive jewelry and bracelets and cases for fine wristwatches without detracting from the quality, durability or appearance of the merchandise.

Abstract: A reflector includes a base body made of a metallic material having substantially the same ionization potential as that of aluminum. A reflecting layer made of aluminum is formed over one surface of the base body by vacuum deposition. A light-transmitting water-insoluble inorganic oxide layer is formed on the aluminum reflecting layer. The light-transmitting inorganic oxide layer has its micropores sealed by H.sub.2 O a carboxylate of an iron family element having a low valence.

Abstract: A reflector includes a base body exhibiting dielectric property at least at its surface. A reflecting layer made of aluminum is formed on one surface of the base body by vacuum deposition. A light-transmitting water-insoluble inorganic oxide layer is formed on the aluminum reflecting layer. The light-transmitting inorganic oxide layer has its micropores sealed by sealing agent comprising H.sub.2 O or a carboxylate of an iron family element having a low valence.

Abstract: An object of the present invention is a method for the anti-wear treatment of the surface of steel parts having a carbon content of at least 0.15% and the coating obtained thereby. The method is characterized by the fact that an addition of sulfur, by depositing of a metal sulfide for example, and a vapor-phase chromizing are carried out in sucession on the surface to be treated.The coating obtained is characterized by the presence of a layer of chromium sulfide on the surface and by the partial recrystallization of the underlying M.sub.7 C.sub.3 chromium carbide layer.The invention can be applied to any moving mechanical system which is subject to abrasion. The invention has importance because it increases the resistance to wear and the life of the system treated while limiting the wear of the untreated opposing part as a result of friction.

Abstract: A reflector has a base body which is made of a metallic material having an ionization potential substantially higher than that of aluminum. An aluminum reflecting layer is formed on one surface of the base body by vacuum deposition. Furthermore, a light-transmitting water-insoluble inorganic oxide layer is formed on the aluminum reflecting layer. The light-transmitting inorganic oxide layer has its micropores sealed by H.sub.2 O or a carboxylate of an iron family element having a low valence. An insulating layer is formed to cover at least the other surface and the peripheral side of the base body.

Abstract: A method of bonding a plurality of thermally stable high strength graphite fiber reinforced glass matrix composite pieces is described. The process comprises applying to the surfaces to be bonded at least one layer of a metal which is highly adherent to the composite and the solder and is oxidatively stable. A tie layer may be used between the composite bond surface and the metal layer to better bond the metal layer to the composite. Following application of the metal layer, the composite pieces are stacked with the metal layers facing each other and a solder layer in between. The temperature of the assembly is raised to melt the solder and form the bond. The melting temperature of the solder and the metal layers are chosen so as to be higher than the use temperature of the bonded composite. A bonded composite article thus formed is also described.

Abstract: A thin film capacitor having a dual bottom electrode is provided. The bottom electrode comprises a first layer of metal and a second layer of platinum, said metal of the first layer being of the nature of forming a stable intermetallic phase with the platinum during heat treatment. The metal of the first layer is typically selected from the group consisting of Hf, Zr, and Ta. The thin film capacitor is suitable for the decoupling capacitor of VLSI.

Abstract: A copper-clad laminate having special utility in the production of high resolution printed circuit patterns by either subtractive or semi-additive processing is made by vapor depositing a film of zinc on a copper film on a silica-coated aluminum carrier sheet, vapor depositing a silica film on the resulting zinc-copper foil, bonding the resulting body to a substrate and then stripping the silica-coated aluminum carrier sheet from the copper-clad laminate.

Abstract: A method of bonding a graphite fiber reinforced glass matrix composite to a metal structure comprising depositing a layer of eutectic alloy metal component to the bond surfaces of the metal and composite followed by placing the thus treated bond surfaces of the metal and composite together with a layer of eutectic alloy containing such metal therebetween. The metal-bond-composite is then heated to melt the alloy and bond the composite to the metal. Articles formed by such a process are also described. The method has particular utility in bonding cooling channel containing metal bases to graphite-glass composite laser mirrors.

Abstract: A method of bonding a plurality of thermally stable high strength graphite fiber reinforced glass matrix composite pieces is described. The process comprises applying to the surfaces to be bonded at least one layer of a metal which is highly adherent to the composite and the solder and is oxidatively stable. A tie layer may be used between the composite bond surface and the metal layer to better bond the metal layer to the composite. Following application of the metal layer, the composite pieces are stacked with the metal layers facing each other and a solder layer in between. The temperature of the assembly is raised to melt the solder and form the bond. The melting temperature of the solder and the metal layers are chosen so as to be higher than the use temperature of the bonded composite. A bonded composite article thus formed is also described.

Abstract: An improved magnetic disk recording device having a smooth recording medium layer covered with a protective film layer whose surface is formed with radially extending sinusoidal jogs or undulations defining a surface roughness greater than that of the underlying recording medium. These jogs act to avoid wear due to the adhesiveness between the device and a recording or reproducing head. The jogged protective film layer is formed by using a solvent of specified boiling point in a spin-coating process.

Abstract: This invention provides a method for preventing reflection. For this purpose and for decreasing the reflecting power of the surface of a light absorbing body of a metal or semi-metal material, the light absorbing body is covered by a light absorbing material of the simple substance of a metal or semi-metal.

Abstract: A structure and method for manufacturing said structure are disclosed for producing a surface of improved smoothness. The result is achieved by applying to the substrate a layer of low melting point metal or low melting point glass and elevating the composite structure to the melting point of said low melting point metal or low melting point glass. The said metal or glass thereupon spreads to a smooth surface of greatly improved roughness.

Abstract: This invention relates to space vehicles. It is concerned with solar absorbers consisting of a metallic or metallized substrate with a weak hemispherical emission factor coated with two layers consisting of a semi-transparent metallic layer adhering to the substrate and of an outer interference dielectric layer. The metallic layer is a layer of nickel/chromium alloy consisting of 60 to 83% by weight of nickel and of 40 to 15% by weight of chromium, and the dielectric layer is a layer of silicon monoxide, of zinc sulphide or silicon dioxide.