Showing papers on "Inert gas published in 2005"

Investigation of the properties of Al1−xCrxN coatings prepared by cathodic arc evaporation

Abstract: Al1−xCrxN coatings prepared by different deposition techniques were investigated in the past, for which excellent oxidation and wear resistance (in comparison to Ti1−xAlxN-coatings) was found. In this work Al1−xCrxN films are deposited from Al1−xCrx targets with various composition (0

Modifying carbon particles with polypyrrole for adsorption of cobalt ions as electrocatatytic site for oxygen reduction

Abstract: Carbon nanoparticles modified with a polypyrrole (PPy) film, impregnated with a solution of a cobalt salt, and heat-treated under an inert atmosphere at 600−700 °C are a good electrocatalyst for the four-electron reduction of O2.

Carbon-doped-Si oxide etch using H2 additive in fluorocarbon etch chemistry

Abstract: Certain embodiments include an etching method (200 and 1600) including providing an etch material (210), applying a gas mixture including hydrogen (230) forming a plasma (240), and etching the etch material (250). The etch material can include a low-k dielectric material. The gas mixture can include a hydrogen gas, a hydrogen-free fluorocarbon, and a nitrogen gas, and further include one or more of a hydrofluorocarbon gas, an inert gas, and/or a carbon monoxide gas. The hydrogen gas can be a diatomic hydrogen, a hydrocarbon, a silane and/or a fluorine-free hydrogen gas, including H2, CH4, C2H4, NH3, and/or H20 gases. The hydrogen­-free fluorocarbon gas can be a CXFY gas (where x≥1 and Y≥1) and the hydrofluorocarbon gas can be a CXHYFZ gas (where x≥1, y≥1 and z≥l). The gas mixture can be free of oxygen. Embodiments can include reduced pressures, reduced hydrogen flow rates and one or more plasma frequencies.

Method of forming a layer and method of forming a capacitor of a semiconductor device having the same

Abstract: In a method of forming a layer using an atomic layer deposition process, after a substrate is loaded into a chamber, a reactant is provided onto the substrate to form a preliminary layer. Atoms in the preliminary layer are partially removed from the preliminary layer using plasma formed from an inert gas such as an argon gas, a xenon gas or a krypton gas, or an inactive gas such as an oxygen gas, a nitrogen gas or a nitrous oxide gas to form a desired layer. Processes for forming the desired layer may be simplified. A highly integrated semiconductor device having improved reliability may be economically manufactured so that time and costs required for the manufacturing of the semiconductor device may be reduced.

Methods of forming phase-change memory devices

Abstract: A method of forming a phase-change non-volatile memory device can include etching-back a spacer insulating layer using a fluorine-based etch gas to form a spacer pattern in an opening in an interlayer dielectric layer and etching the spacer insulating layer in the opening using an inert gas.

High-density plasma (HDP) chemical vapor deposition (CVD) methods and methods of fabricating semiconductor devices employing the same

Abstract: In one embodiment, a semiconductor substrate is placed into a process chamber. A gas mixture including a silicon-containing gas, a fluorine-containing gas, an inert gas, and an oxygen gas is introduced into the chamber at a pressure range of from about 30 mTorr to about 90 mTorr. During this time, deposition and etching processes are concurrently performed using a plasma to form a high-density plasma (HDP) insulating layer on the semiconductor substrate. A ratio of deposition to etching is from about 3:1 to about 10:1. A ratio of a flow rate of the fluorine-containing gas to a flow rate of the silicon-containing gas is less than about 0.9.

Ultra-active Fe/ZSM-5 catalyst for selective catalytic reduction of nitric oxide with ammonia

Abstract: We report a Fe/ZSM-5 catalyst that has higher catalytic activities for the selective catalytic reduction (SCR) of NO by ammonia as compared to other known catalysts. This Fe/ZSM-5 catalyst was prepared by a simple impregnation method using NH 4 -ZSM-5 and FeCl 2 . The preparation process is in fact a combination of the conventional impregnation and solid-state ion exchange but the gas atmosphere for calcination is not an inert gas. Another process in which the Fe/ZSM-5 sample was first calcined in an inert gas (He) instead of air and then calcined in air was also investigated, and the activities of the catalysts prepared by these two processes were not different by much, which indicated that even in air the exchange between NH 4 + and Fe 2+ took place as evidenced by the ESR results and that the exchange was incomplete. Such incomplete exchange led to the formation of Bronsted type acid in the catalysts after the decomposition of NH 4 -ZSM-5, which is considered as the active site for ammonia adsorption. XRD and TEM clearly showed that there existed fine iron oxide particles located on the external zeolite surfaces. XPS results show that, unlike the Fe-ZSM-5 catalyst prepared by aqueous ion exchange, large amount of Fe 2+ species were found in the Fe/ZSM-5 catalyst prepared by this method. Compared to the activities of different Fe/ZSM-5 catalysts, the existence of the Fe 2+ species and the highly dispersed FeO x species may have contributed to the high activity of this Fe/ZSM-5 catalyst, especially in the low temperature ranges. Characterization of the catalyst and the reaction mechanism were also investigated by FTIR.

Formation technology for nanoparticle films having low dielectric constant

Abstract: A method for forming a low dielectric constant film includes the steps of: introducing reaction gas comprising an organo Si gas and an inert gas into a reactor of a capacitively-coupled CVD apparatus; adjusting a size of fine particles being generated in the vapor phase to a nanometer order size as a function of a plasma discharge period inside the reactor; and depositing fine particles generated on a substrate being placed between upper and lower electrodes inside the reactor while controlling a temperature gradient between the substrate and the upper electrode at about 100° C./cm or less.

Door plate for furnace

Abstract: The process chamber of a vertical furnace is provided with a closure, or door, comprising an upper and a lower door plate. The upper door plate has a gas exhaust opening proximate its center, thereby allowing for a symmetrical flow of process gases through the process chamber and into the gas exhaust opening. The upper door plate is spaced from the lower door plate to form a sealing chamber, which is purged with inert gas. Optionally, both the gas exhaust opening and the sealing chamber empty into a gas exhaust channel formed inside the upper door plate. The gas exhaust channel leads to an exhaust which exhausts gases from the furnace and separates the flow path of corrosive process gases from surfaces of the lower door plate, which may be formed of relatively easily-corroded metal.

Method for producing rare earth permanent magnet material

Abstract: A method for producing a rare earth permanent magnet material, characterized in that it comprises providing a sintered magnet article comprising an R1-Fe-B based composition (wherein R1 represents one or more selected from the rare earth elements including Y and Sc) and a powder containing one or more selected from an oxide of R2, a fluoride of R3 and an acid fluoride of R4 (wherein R2, R3 and R4 represent one or more selected from the rare earth elements including Y and Sc, respectively), causing the powder to be present on the surface of said magnet article, and subjecting said magnet article and powder to a heat treatment at a temperature of the sintering temperature for said magnet or lower under vacuum or in an inert gas. The above method allows the production of a miniature or thin high performance permanent magnet having a high residual magnet flux density and high coercive force, with high productivity.

Fabrication of lotus-type porous stainless steel by continuous zone melting technique and mechanical property

Abstract: Lotus-type porous stainless steel (SUS304L) rods were fabricated by the continuous zone melting technique under a pressurized mixed gas of hydrogen and inert gas such as argon or helium. Pores with cylindrical shape, whose growth direction is parallel to the solidification direction, are observed in the rods. The dependence of the porosity and averaged pore diameter on the partial pressure of hydrogen or the total pressure and on the transference velocity of rods was investigated. It was found that the porosity increases with increasing partial pressure of hydrogen under a constant total pressure and the pore diameter decreases with increasing transference velocity. The maximum porosity was about 60 pct under the experimental conditions in the present work. The observation of the microstructure and the measurement of the tensile strength were also carried out.

Numerical investigation of a diffusion absorption refrigeration cycle

Abstract: A thermodynamic model was developed for an ammonia–water diffusion absorption refrigeration (DAR) cycle with hydrogen or helium as the auxiliary inert gas, manufactured by Electrolux Sweden (currently known as Dometic). The performance of the system was examined parametrically by computer simulation. Mass and energy conservation equations were developed for each component of the cycle and solved numerically. The model was validated by comparison with previously published experimental data for DAR systems. Investigation of cycle performance under different conditions indicated that the best performance was obtained for a concentration range of the rich solution of 0.2–0.3 ammonia mass fraction and that the recommended concentration of the weak solution was 0.1. It was also found that as the degree of rectification decreased, the performance of the DAR cycle decreased. Finally, the study showed that helium was superior to hydrogen as the inert gas: the coefficient of performance of a DAR unit working with helium was higher by up to 40% than a cycle working with hydrogen.

Pressure dependence of the vapor-liquid-liquid phase behavior in ternary mixtures consisting of n-alkanes, n-perfluoroalkanes, and carbon dioxide.

Abstract: Expansion of an organic solvent by an inert gas can be used to tune the solvent's liquid density, solubility strength, and transport properties In particular, gas expansion can be used to induce miscibility at low temperatures for solvent combinations that are biphasic at standard pressure Configurational-bias Monte Carlo simulations in the Gibbs ensemble were carried out to investigate the vapor-liquid-liquid equilibria and microscopic structures for two ternary systems: n-decane/n-perfluorohexane/CO2 and n-hexane/n-perfluorodecane/CO2 These simulations employed the united-atom version of the transferable potential for phase equilibria (TraPPE-UA) force field Initial simulations for binary mixtures of n-alkanes and n-perfluoroalkanes showed that special mixing parameters are required for the unlike interactions of CHx and CFy pseudoatoms to yield satisfactory results The calculated upper critical solution pressures for the ternary mixtures at a temperature of 298 K are in excellent agreement with the available experimental data and predictions using the SAFT-VR (statistical associating fluid theory of variable range) equation of state The simulations yield asymmetric compositions for the coexisting liquid phases and different degrees of microheterogeneity as measured by local mole fraction enhancements

Influences of drying and storage of lycopene-rich carrots on the carotenoid content

Abstract: The stability of β-carotene and lycopene was investigated during convective air and inert gas drying, microwave vacuum drying, and freeze-drying for lycopene containing carrots (Daucus carota L. cv. Nutri Red). After convection drying at temperatures below 70°C, β-carotene and lycopene contents remained unchanged independent of the drying medium. Freeze-drying did not show any advantage to convection-drying regarding carotenoid retention. Microwave vacuum–drying led to dry products with high carotenoid retention within very short drying times of about 2 h. Storage in air and in inert gas (nitrogen) containers was studied for convection-dried products, observing a better retention of carotenoids when using inert gas for a period of up to 6 months. After convection- and microwave vacuum–drying, an even better carotenoid extractability could be observed. No changes in the isomere fractions could be detected in any case.

Method for obtaining carbon nanotubes on supports and composites comprising same

Abstract: The invention concerns a method for obtaining carbon nanotubes by CVD growth on nano/micrometric supports, characterized in that it comprises : adding a carbon source compound containing a catalyst, under an inert gas and hydrogen current. The invention is applicable to the manufacture of multiple-scale composites.

On the Microstructure of the Initial Oxide Grown by Controlled Annealing and Oxidation of a NiCoCrAlY Bond Coating

Abstract: Different pre-annealing and pre-oxidation treatments were conducted on a dual phase γ+β Ni–21Co–18Cr–22Al–0.2Y (at.%) bond coating for 1 hr at 1373 K (i) with or without a native oxide upon heating, (ii) in two different atmospheres upon heating, and (iii) under various oxygen partial pressures (pO2) in the range of 0.1–105 Pa during oxidation. The chemical composition, structure, morphology and phase constitution of the resulting oxide layers were investigated using a range of analytical techniques. It is found that the exclusive formation of a continuous α-Al2O3 layer without the simultaneous formation of NiAl2O4 spinel was promoted for oxidation at low pO2. The formation of metastable θ-Al2O3 was suppressed for a low fraction of the β phase, coupled with a high fraction of segregated Y at the initial bond coat surface. Initial Y segregation and incorporation of Y2O3 and Y3Al5O12 within the developing oxide layer was promoted in the absence of a native oxide and for heating in an inert atmosphere. The development of protrusions (i.e. pegs) at the oxide/coating interface, as a result of the incorporation of internal Y2O3 precipitates by the inward growing oxide layer, was most pronounced upon heating in an inert atmosphere, followed by oxidation at an intermediate pO2.

Burner and method for induction of flue gas

Abstract: A low NO x burner and method wherein (a) combustion air flows through the interior of the burner in a manner effective for drawing an amount of inert flue gas diluent from the fired heating system into the combustion air stream, preferably via one or more induction channels provided through the burner wall, and/or (b) air or an inert gas is discharged into the induction channel(s) in a manner effective for delivering flue gas into the combustion air stream.

Method of forming a metal film for electrode

Abstract: A method of forming a refractory metal film doped with III or V group elements. The first process gas is supplied from a first gas source through a first gas introducing member to and through a gas supply mechanism toward a substrate within a processing vessel. The second process gas is supplied from a second gas source through a second gas introducing member to and through the gas supply mechanism toward the substrate within the processing vessel. The processing vessel is purged by evacuating the processing vessel by an evacuating mechanism, while supplying the inert gas from a third source through a third gas introducing member to and through the gas supply mechanism into the processing vessel. The supplying the first process gas and the supplying the second process gas are repeated with the supplying the purging gas being carried out between supplying the first and second gases performed so that residual gas present in the processing vessel after performing the supplying of the first and second process gases is reduced to a level of 1 to 30% based on the entire capacity of the processing vessel.

Influence of Non‐Polymerizable Gases Added During Plasma Polymerization

Abstract: In plasma polymerization often additional, non-polymerizable gases are used, either as carrier gas or as reactive co-monomer. The gas ratio represents an additional parameter, which complicates the understanding of plasmapolymerization processes. Therefore, we thoroughly investigated the deposition rates of different gas mixtures (O 2 / HMDSO, N 2 and NH 3 /C x H y , as well as inert gas/C x H y ) on the basis of a macroscopic approach. Since the mass deposition rates depend on the specific energy W/F, the plasma polymerization regime for the corresponding polymerizable monomer can be identified by introduction of a modified flow F = F m + a F c (sum of monomer flow F m and carrier gas flow F c with a flow factor a). Any deviations discovered during application of this novel approach indicate additional effects, such as ion-induced effects.

Method and apparatus for generating an inert gas on a vehicle

Abstract: An inert gas generating system for generating inert gas on a vehicle having a fuel tank and a fuel tank vent The system includes an inlet for receiving a flow of gas having a nitrogen component and an oxygen component from a gas source, a heat exchanger downstream from the inlet and in fluid communication with the inlet for cooling gas received from the inlet, and a gas separation module downstream from the heat exchanger and in fluid communication with the heat exchanger for separating gas received from the heat exchanger into a nitrogen-enriched gas flow and an oxygen-enriched gas flow The gas separation module is adapted to deliver nitrogen-enriched gas from the nitrogen-enriched gas flow to the fuel tank without delivering the nitrogen-enriched gas through the fuel tank vent The gas separation module is also adapted to deliver nitrogen-enriched gas from the nitrogen-enriched gas flow to the fuel tank vent

Atom Collision-Induced Resistivity of Carbon Nanotubes

Abstract: We report the observation of unusually strong and systematic changes in the electron transport in metallic single-walled carbon nanotubes that are undergoing collisions with inert gas atoms or small molecules. At fixed gas temperature and pressure, changes in the resistance and thermopower of thin films are observed that scale as roughly M1/3, where M is the mass of the colliding gas species (He, Ar, Ne, Kr, Xe, CH4, and N2). Results of molecular dynamics simulations are also presented that show that the maximum deformation of the tube wall upon collision and the total energy transfer between the colliding atom and the nanotube also exhibit a roughly M1/3 dependence. It appears that the transient deformation (or dent) in the tube wall may provide a previously unknown scattering mechanism needed to explain the atom collision–induced changes in the electrical transport.