摘要:
In high-tech fields such as electronics, the development of new high performance materials which differ from conventional materials has received much attention. An object of the present invention is to provide a clathrate compound which can be used as a thermoelectric material, a hard material, or a semiconductor material. Atoms of an element from group 4B of the periodic table are formed into a clathrate lattice, and a clathrate compound is then formed in which specified doping atoms are encapsulated within the clathrate lattice, and a portion of the atoms of the clathrate lattice are substituted with specified substitution atoms. Suitable doping atoms are atoms from group 1A, group 2A, group 3A, group 1B, group 2B, group 3B, group 4A, group 5A, group 6A, and group 8, and suitable substitution atoms are atoms from group 1A, group 2A, group 3A, group 1B, group 2B, group 3B, group 5A, group 6A, group 7A, group 5B, group 6B, group 7B, and group 8 of the periodic table. Suitable manufacturing methods include melt methods and sintering methods, and moreover intercalant intercalation compounds or the like may also be used as raw materials.
摘要:
A method including the steps of (a) depositing a metal layer on a selected portion of a silicon substrate under a first set of predetermined conditions to form an metal silicide layer and an intermediate n-type silicon layer; and (b) exposing the metal silicide layer and the n-type silicon layer to a second set of predetermined conditions to form a silicon clathrate film on the selected portion of the silicon substrate, where the intermediate n-type silicon layer acts to bond the silicon clathrate to the silicon substrate to form a silicon clathrate structure.
摘要:
Novel ceramic-metal intercalation compounds useful in the formation of densified ceramic-metal articles are prepared, for instance, by exposing a ceramic to an organometallic compound in a low dielectric solvent. The use of the ceramic-metal compounds in the formation of articles by densification allows achievement of densified compositions having at least one of increased density, hardness, and toughness.
摘要:
The present invention relates to a process for the production of fine powder materials and the products of that process. The process involves the in-situ precipitation of second phase particles, such as ceramic or intermetalics, within a metal matrix, followed by separation of the particles from the matrix to yield a powder comprising the second phase particles. Particles formed by this process are typically in the size range of 0.01 to 10 microns and have controlled morphology, narrow size distribution, well defined stoichiometery and relatively high purity. Exemplary of second phase particles formed by this process are metal borides, carbides, nitrides, oxides, silicides and beryllides, including TiB.sub.2, ZrB.sub.2, VB.sub.2, MoB.sub.2, TiC, WC, VC, TiN, ZrSi.sub.2, MoSi.sub.2, Ti.sub.5 Si.sub.3, and TiBe.sub.12.
摘要:
Preparation of metal carbides, nitrides, borides, silicides and phosphides, also metal alloys and pure metals, by providing a precursor in which there are organic ligands bonded to the metal or metals, such precursor having the element X also bonded directly or indirectly to the metal or metals, the ligand-metal bonding being weaker than the X-metal bonding whereby on pyrolysis the product M.sub.a X.sub.b results in which M represents the metal or metals, X represents C, N, B, Si, P and a and b represent the atomic proportions of M and X. The subscript b may be zero if an alloy or pure metal is to be prepared. The product M.sub.a x.sub.b can be prepared by relatively low temperature pyrolysis and the precursor can be used as a solution or a low melting solid. This enables one to apply a surface coating or to shape the precursor into a fiber, rod or other shape and to pyrolyze the coating or shaped article. M is a transition, lanthanide or actinide metal or tin.
摘要:
A method of producing ultrafine powders comprising metal silicide powder and the products produced by the method are disclosed. The ultrafine powders comprising metal silicide powders are ideally suited to form stable colloidal suspensions which are used in the production of conductive metal silicide containing films. The process employs gaseous reactants comprising a metal halide and a silicon-containing compound. The reactants are exposed to high intensity light to produce ultrafine powders. In addition to the production of metal silicide powders, the ultrafine powders may also include silicon powder and metal subhalide powder. The ultrafine powders are particularly suited for use in VLSI and VVLSI production.
摘要:
Helical flow of hot plasma gas, e.g., hydrogen gas, produced by a gas vortex stabilized plasma arc is cancelled by introducing attenuating gas, e.g., hydrogen gas, into the hot plasma gas in a manner such that the attenuating gas assumes a vortical direction opposite to the helical flow of the hot plasma gas. The resulting gas stream is well-collimated. The well-collimated plasma gas stream is used in the preparation of finely-divided refractory metal and metalloid carbides, borides, nitrides, silicides and sulfides. Reactants for the preparation of the aforementioned refractory powders are introduced into the collimated plasma gas stream. The reaction is conducted in the gas phase within a reactor and solid, finely-divided refractory powder removed from the reactor.
摘要:
Apparatus for establishing a substantially expanded electric arc discharge between a circulating electrode which includes the use of plasma guns, and a coacting stationary annular electrode through which the discharge effluents emerge. Means for introducing particulate material into the expanded arc discharge and operating the latter as an expanded arc furnace for various chemical reactions including the reduction and separation of ores, melting, refining, comminuting, spheroidizing and coating.
摘要:
A METHOD OF PRODUCING REFRACTORY INORGANIC COMPOUNDS SUCH AS CARBIDES, BORIDES, NITRIDES, SILICIDES, OXIDES, PHOSPHIDES, SULPHIDES, FLUORIDES AND CHLORIDES OF METALS OF THE IV, V AND VI GROUPS, IN WHICH AT LEAST ONE OF THE METALS OF THE IV, V AND VI GROUPS OF THE PERIODIC SYSTEM IS MIXED WITH ONE OF THE NON-METALS N, C, B, SI, O2, P, S, F, OR CL2 AND TO THE RESULTING MIXTURE IS INTRODUCED IGNITION MEANS FOR GENERATING A TEMPERATURE SUFFICIENT FOR STARTING THE PROCESS OF COMBUSTION OF THE INITIAL COMPONENTS WHOSE FURTHER INTERACTION TAKES PLACE OWING TO HEAT HENERATED BY THE REACTION, THE REACTION OF METALS WITH METALLOIDS, C, B, SI, P, S BEING CARRIED OUT IN AN INERT GAS MEDIUM.
摘要:
BINARY CRABIDWS, BORIDES AND SILICIDES, SUCH AS TUNGSTEN CARBIDE, HAVING AN AVERAGE PARICLE SIZE OF LESS THAN A MICRON, ARE PREPARED BY REACTING A PAIR OF SUITABLE REACTANTS SUCH AS TUNGSTIC OXIDE AND CALCIUM CARBIDE, IN A MOLTEN METAL HALIDE BATH SUCH AS SODIUM CHLORIDE, AT A TEMPERATURE OF BETWEEN 200 AND 1200*C. IN THE PRESENCE OF AN ALKALI METAL OR ALKALINE EARTH METAL REDUCING AGENT. THE BINARY COMPOUNDS THUS PRODUCED ARE PARTICULARLY USEFUL IN PREPARING HARD, DENSE REFRACTORY MATERIALS.