摘要:
A multilayer superconducting thin film composite article, comprising a carbon-containing substrate, and an interlayer comprising a material selected from the group consisting of zirconium, yttrium, niobium, and carbides and oxides thereof, platinum, iridium, gold, palladium, and silver, and an overlayer comprising an HTSC material. The carbon-containing substrate preferably comprises diamond and the interlayer preferably comprises a zirconium carbide sub-layer at the interface with the substrate, an intermediate sub-layer of zirconium metal, and an outer sub-layer of zirconium oxide at the interface with the HTSC material overlayer. The superconducting thin film material may comprise a copper oxide HTSC material, with YBaCuO, TlBaCaCuO, and BiSrCaCuO HTSC materials being preferred. The interlayer accommodates formation of the superconducting film in an oxic environment at elevated temperature without destruction of the substrate, while at the same time protecting the HTSC material in the overlayer from deleterious reaction with the substrate which otherwise may cause the HTSC material or precursor thereof to be highly resistive, i.e., non-superconducting, in character. The invention thus permits the fabrication of devices incorporating HTSC films with carbon-containing substrates such as diamond, including high operating temperature bolometers, and high power, high speed switching devices.
摘要:
A static magnetic memory includes a layer having a plurality of vertically oriented and shape-anisotropic elongated ferromagnetic particles. A plurality of writing conductors are adjacent the layer, and the conductors selectively apply magnetic fields to selected regions of the layer by directing electrical current to magnetize the particles in an up or down direction. Static reading means detect the direction of magnetization. The particles may include a soft magnet portion and a hard magnet portion. In another preferred embodiment, a material and a method of making same includes providing a matrix full of elongated holes, depositing a first magnetic material having a first coercivity into the holes, and then depositing a second magnetic material having a second coercivity into the holes to form a composite elongated particle in each hole.
摘要:
A magnetically shape-anisotropic material is made by providing a matrix with a plurality of elongated holes, and depositing first and second magnetic materials in each hole so as to form elongated particles including the first material adjacent one end and the second material adjacent the opposite end. One of the materials is a magnetically soft material having relatively low coercivity whereas the other material is a magnetically hard material having relatively high coercivity. The particles have dimensions transverse to their axes of elongation smaller than the magnetic domain size of the magnetically soft material.
摘要:
A textured substrate is disclosed which is amenable to deposition thereon of epitaxial single crystal films of materials such as diamond, cubic boron nitride, boron phosphide, beta-silicon carbide, and gallium nitride. The textured substrate comprises a base having a generally planar main top surface from which upwardly extends a regular array of posts, the base being formed of single crystal material which is crystallographically compatible with epitaxial single crystal materials to be deposited thereon. The single crystal epitaxial layers are formed on top surfaces of the posts which preferably have a quardrilateral cross-section, e.g., a square cross-section whose sides are from about 0.5 to about 20 micrometers in length, to accommodate the formation of substantially defect-free, single crystal epitaxial layers thereon. The single crystal epitaxial layer may be selectively doped to provide for p-type and p.sup.+ doped regions thereof, to accommodate fabrication of semiconductor devices such as field effect transistors.
摘要:
A microdynode electron multiplier provides numerous microchannels extending parallel to one another through a layered structure incorporating insulating spacer layers and dynode layers which either incorporate a conductive electrode layer or are contiguous with a conductive electrode layer. The dynode layers include materials with high electron emissivity. The dynode layers can be biased to different electrical potentials to provide a potential gradient along the length of each microchannel. Multi-stage electron multiplication provides high gain. The device desirably is formed as a monolithic, sealed structure with a cathode structure such as a photocathode and an anode structure. The device can provide a multi pixel imaging device of extremely high sensitivity and resolution.
摘要:
N-type semiconducting diamond is disclosed, which is intrinsically, i.e., at the time of diamond formation, doped with n-type dopant atoms. Such diamond is advantageously formed by chemical vapor deposition from a source gas mixture comprising a carbon source compound for the diamond, and a volatile precursor compound for the n-type impurity species, so that the n-type impurity atoms are doped in the diamond film in situ during its formation. By such in situ formation technique, shallow n-type impurity atoms, e.g., lithium, arsenic, phosphorous, scandium, antimony, bismuth, and the like, may be incorporated into the crystal lattice in a uniform manner, and without the occurrence of gross lattice asperities and other lattice damage artifacts which result from ion implanation techniques. A corresponding chemical vapor deposition method of forming the n-type semiconducting diamond is disclosed. The n-type semiconducting diamond of the invention may be usefully employed in the formation of diamond-based transistor devices comprising pn diamond junctions, and in other microelectronic device applications.
摘要:
A textured substrate is disclosed which is amenable to deposition thereon of epitaxial single crystal films of materials such as diamond, cubic boron nitride, boron phosphide, beta-silicon carbide, and gallium nitride. The textured substrate comprises a base having a generally planar main top surface from which upwardly extends a regular array of posts, the base being formed of single crystal material which is crystallographically compatible with epitaxial single crystal materials to be deposited thereon. The single crystal epitaxial layers are formed on top surfaces of the posts which preferably have a quadrilateral cross-section, e.g., a square cross-section whose sides are from about 0.5 to about 20 micrometers in length, to accommodate the formation of substantially defect-free, single crystal epitaxial layers thereon. The single crystal epitaxial layer may be selectively doped to provide for p-type and p.sup.+ doped regions thereof, to accommodate fabrication of semiconductor devices such as field effect transistors.
摘要:
A silicon element having macrocavities beneath its exterior surface is fabricated by electrochemical etching of a p-type silicon wafer. Etching at a high current density results in the formation of deep macrocavities overhung by a layer of crystalline silicon. The process works with both aqueous and non-aqueous electrolytes.
摘要:
A microchannel plate and method of manufacturing same is provided. The microchannel plate includes a plate consisting of an anodized material and a plurality of channels which are formed during the anodization of the material and extend between the two sides of the plate. Electrodes are also disposed on each side of the plate for generating an electrical field within the channels. Preferably, the material is alumina and the channels are activated such that the channel walls are conductive and highly secondary emissive.
摘要:
An element with elongated, high aspect ratio channels such as microchannel plate is fabricated by electrochemical etching of a p-type silicon element in a electrolyte to form channels extending through the element. The electrolyte may be an aqueous electrolyte. For use as a microchannel plate, the; the silicon surfaces of the channels can be converted to insulating silicon dioxide, and a dynode material with a high electron emissivity can be deposited onto the insulating surfaces of the channels. New dynode materials are also disclosed.