Showing papers on "Barrier layer published in 1974"

Structure and method for producing an image

Abstract: A new structure comprising a layer of an imaging material, capable of undergoing an image forming change in response to energy, a layer of a barrier material and a layer of a catalyst material which, if necessary after activation, is capable of causing or promoting the image forming change in the imaging material The barrier material is capable of controlling in accordance with a desired image pattern, the passage of the catalyst material through the barrier layer into contact with the imaging material in selected areas, while it prevents passage of the catalyst material in other selected areas The permeability of the barrier layer for the catalyst material and, if necessary the activation of the catalyst material, may be controlled by the selective imagewise application of imaging energy to the structure, and the image forming change in the imaging material may be brought about by the application of development energy, such as heat, to the structure to produce a detectable image in the layer of the imaging material

Nozzles formed in monocrystalline silicon

Abstract: Method for producing a predetermined pattern of small size fluid nozzles of identical or different geometries in crystallographically oriented monocrystalline silicon or similar material utilizing anisotropic etching through the silicon to an integral etch resistant barrier layer heavily doped with P type impurities.

Metal-silicide Schottky diode employing an aluminum connector

Abstract: In a Schottky diode of the type wherein a metal silicide layer interfaces with a silicon semiconductive body to form a Schottky diode, an inert barrier layer of a refractory metal, such as Mo, Ti, W, Ta and alloys thereof, is deposited overlaying and in electrical contact with the metal silicide layer An aluminum electrical connector electrode is deposited overlaying the barrier layer for intraconnecting the Schottky diode with other devices The refractory barrier layer prevents the aluminum from diffusing into or otherwise reacting with the metal silicide layer in such a way as to deleteriously affect the performance of the Schottky diode

Stabilized high-field superconductor

Abstract: A superconducting compound of the A-15 crystal structure type is obtained in a composite by a high temperature diffusion between a first metallic component and a second metallic component contained in a bronze alloy. Stability is achieved by including in the composite a quantity of high-conductivity normal material. Diffusion of the second metallic component into the normal material with a resultant degradation of conductivity of the normal material is prevented by placing an impervious barrier layer between the bronze alloy and the normal material. In a specific embodiment, the barrier layer takes the form of an annular shell comprising at least two sectors of dissimilar metals, one of which reacts with a component of the bronze alloy to form a layer of said superconducting compound, and the other of which is substantially non-reactive. Thus, a discontinuous superconducting ring is formed on the barrier layer which prevents flux trapping.

Method for producing a tubular multi-layered porous barrier

Abstract: A method for producing a tubular multi-layered porous barrier comprising the step of depositing fine powder onto at least one of the inner and outer surfaces of a sintered tubular porous support member in a layer of uniform thickness to form a fine powder layer and pressurizing said powder layer against said support member to form a porous barrier layer on the support member.

Surface protected magnetic recording members

Abstract: It is known to manufacture a recording member having a substrate supporting a magnetic recording alloy on a surface and to locate a protective covering on the surface of the alloy remote from the substrate. An improved protective covering for use in this combination comprises a barrier layer located on the surface of the recording alloy and an oxide layer located on the surface of the barrier layer remote from the recording alloy. The barrier layer preferably consists of a nonmagnetic material. The oxide layer is also nonmagnetic and is sufficiently thick to protect the magnetic alloy layer against surface abrasion. The barrier layer isolates the oxide layer from the magnetic recording layer so as to preserve the character and uniformity of the magnetic recording layer as the oxide layer is created.

Process for the production of a multiple layer laminate

Abstract: Disclosed is a process for producing a laminate having at least three layers comprising a base layer of polystyrene, an intermediate layer of an ABS polymer and a third barrier layer of a vinyl chloride or vinylidene chloride polymer comprising the steps of co-extruding through a single die orifice a heat plastified composite structure comprising a base layer of polystyrene and a surface layer of an ABS polymer and thereafter laminating a preformed layer of a barrier material polymer to the ABS surface layer of the co-extruded composite.

The Morphology of Anodic Films Formed on Aluminium in Oxalic Acid

Abstract: SummaryElectron microscopy of carbon replicas taken from outer surfaces, sections and cell base patterns of anodic films, formed in oxalic acid, has enabled relationships between the main film parameters of barrier layer thickness, cell size and pore diameter to be quantified and related to the anodizing variables. In general, the barrier layer, cell and pore dimensions are all proportional to the forming voltage and are inter-related as a result of the forming mechanism involving field-assisted dissolution and growth of the film in the barrier layer region. If the forming voltage is allowed to rise during the anodizing run at constant current density, inversely funnelled pores are produced in which the pore diameter is smaller nearer the film surface than adjacent to the barrier layer. In order to maintain this morphology it is necessaiy to restrain the electrolyte aggressiveness by controlling the acid concentration and temperature below certain limits. Transmission electron micrographs of stripped thin...

Metal coated articles

Abstract: A transparent container is provided which is coated on the interior surface with a coherent barrier layer of metal. Stainless steel is a preferred barrier coating for glass equipment adapted to contain biological media.

Process and electrolyte for applying barrier layer anodic coatings

Abstract: Various metals may be anodized, and preferably barrier anodized, by anodizing the metal in an electrolyte comprising quaternary ammonium compound having a complex metal anion in a solvent containing water and a polar, water soluble organic material.

Method of making drill proof plate for safes

Abstract: A plate structure for safes, vaults and the like, and a method of making it, wherein the plate comprises two or more metallic sheets fused together to form a unitary structure. The plate structure has a barrier layer of hard particles such as carbide particles and the like embedded in the line of fusion between adjacent metallic sheets. Adjacent metallic sheets are provided with layers of borax and a layer of hard particles therebetween, heated to a temperature of from 2300*F to 2400*F and subjected to a pressure in the order of 2500 tons.

Organic electronic rectifying devices

Abstract: There are described herein organic electronic devices of the acceptor-donor (A-D), acceptor-donor-acceptor (A-D-A), donor-acceptor-donor (D-A-D), acceptor-donor-acceptor-donor (A-D-A-D), types analogous to the p-n, p-n-p, n-p-n and p-n-p-n types in typical semiconductor devices. The A-D device suitably comprises a support or substrate upon which there is provided a layer of a conductive metal. On this metallic layer, there is provided in a thickness of about 25 to 50 Angstroms, a barrier layer organic compound. On the latter compound, there is provided a deposited metal conductor, the metal depositing suitably being effected by a technique such as vapor deposition. The A-D-A and D-A-D devices comprise a semiconductor or metallic body, on each surface of which there is provided in about a 25 to 50 Angstrom thickness, the aforementioned barrier layer compound. On each compound layer there is deposited a metal conductor. The barrier layer compound suitably is one whose molecules consist of two nonsymmetric, i.e., not same energy level, reversible redox portions separated by a tunneling bridge.

Current confining light emitting diode

Abstract: The resistivity of particular layers of a gallium arsenide-gallium aluminum arsenide light emitting diode is altered to provide current confinement in the central regions around the well hole. This is accomplished by proton bombardment to increase resistivity of layers around the lower metal contact area while leaving a low resistivity path over the contact, by diffusion of a low resistivity region into an added high resistivity layer adjacent the light emitting well hole, or by diffusion into a reverse conductivity barrier layer over the lower metal contact area.

Lateral semiconductive device and method of making same

Abstract: A lateral semiconductive device, such as a Gunn device or Impatt diode, is fabricated by depositing a barrier layer of beryllia over an epitaxial grown layer of N- type semiconductive material on an N+ type semiconductive wafer. The wafer is then thinned down, as by grinding and polishing. Electrode material is then deposited overlaying the N+ wafer layer for making ohmic contact thereto. The electrode material is etched to define at least a pair of laterally spaced electrodes, each making electrical connection to the epitaxial N- layer via the intervening layer of N+ wafer material. In the case of a Gunn device, the insulative barrier layer provides electrical insulation and prevents undesired leakage of current. In addition, it serves as a barrier to prevent metallic contact materials from diffusing into the epitaxial N- layer. Further, it serves as a heat sink between the active device and its mount. The electrode contacts are improved by their ohmic contact to the N+ wafer material on which the epitaxial N- active layer is grown.

Distribution of Phosphate Ions in the Porous Anodic Oxide Film Formed on Aluminium in Phosphoric Acid Solution

Abstract: A porous oxide film having parallel pores is produced when aluminium is anodized in such a solution as phosphoric acid and a thin compact oxide layer called the barrier layer exists at the bottoms of pores, The thickness of pore-wall, which is a half of the distance between the adjacent pores, is nearly the same as that of the barrier layer, b (Fig. 1). lt has been known that a small amount of phosphate ion is included in the film as the result of coordination of these iions towards aluminium ions in the oxide.In this investigation, the distribution of phosphate ion across pore-wall( =1000A) was measured for the film formed at 100 V (vs. SCE) in 4% HsPO kept at 250C, a technique of dissolving the film in 2 mol/l H2SOG solution being utilized. The dissolution of. the filrp proceedsYff the surface of pore-wall in such a manner that pore widens evenly. all thro.ugh ihe depth of the pore (Fig. 1), so that the distribution of, phosphate ion was determined-by measur the time-variations of the amounts of phosphate and aluminium ions in solutio4 during dissolution (Fig. 2). The concentration of phosphate izefo at 900 A (Fig. 4). The average concentration of phosphate be abeut O.14 mg-PO/rng-Al. The to that across the pore-waH, in view o eiectronmicroscepy. The mechani sm of film growth explaining described. nearly constant irrespective of, but increases gradually and decreases nearly equal to in the film was estimated to distribtition of phosphate across the barrier laYer was similar of the results of examination of the film by ESCA and the phosphate distribution is described.

High power field effect transistor

Abstract: A field effect transistor is provided wherein conductive mesas are topped by source and drain electrodes, respectively, and rise out of a semiconductor epitaxial layer onto which there is formed a Schottky barrier layer. A heat sink metal layer backs the barrier layer and forms a gate terminal for control of flow of current between the source and drain electrodes via the epitaxial layer adjacent to the barrier.

Polysulphone dialysis membrane - having a barrier layer on one side

Abstract: Polysulphone dialysis membrane has a barrier layer at the surface backed by a more porous support layer. The membrane having a dialytic resistance to NaCl of 50 min/cm. and a flux between 3 x 10-5 and 1 x 10-6 ml/cm2 min. mm Hg. The membrane is supported with one side contacting a dialysable liquid and the other side contacting a solvent for the dialysable components.

Holographic recording medium

Abstract: A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

Welding together high and low-alloyed steels - using niobium-contg low-all-oyed steel barrier to prevent migration of carbon into weld

Abstract: Barrier layer consisting of Nb-contg. low-alloyed steel is preliminarily formed on the surface of an unalloyed or low-alloyed steel body, and only then the body is welded to a high-alloyed steel body or surfaced with high alloyed steel. Carbon migration into the weld is suppressed because Nb binds carbon atoms in the barrier layer. Nb can be replaced partly or wholly by other carbice-forming metals such as Ta, Ti, V, W or Mo. This method can be applied to the construction of machines, chemical appts., nuclear installations, etc.