A method of making an atomic layer nanoribbon that includes forming a double atomic layer ribbon having a first monolayer and a second monolayer on a surface of the first monolayer, wherein the first monolayer and the second monolayer each contains a transition metal dichalcogenide material, oxidizing at least a portion of the first monolayer to provide an oxidized portion, and removing the oxidized portion to provide an atomic layer nanoribbon of the transition metal dichalcogenide material. Also provided are double atomic layer ribbons, double atomic layer nanoribbons, and single atomic layer nanoribbons prepared according to the method.

Described are yttrium fluoride compositions, including deposited films, e.g., coatings, that contain yttrium fluoride; methods of preparing yttrium fluoride compositions and deposited film coatings that contain yttrium fluoride; as well as substrates that have a deposited film coating that contains yttrium fluoride at a surface and methods and equipment that include the substrates.

The present disclosure relates to methods and systems for producing structured carbon materials in a microgravity environment. A benefit of the methods and systems disclosed herein can include producing structured carbon materials having fewer defects and reducing excess carbon dioxide in an atmosphere by converting carbon dioxide from an ambient gas into a structured carbon material.

A vapor phase epitaxial growth device comprises a reactor vessel. The device comprises a wafer holder arranged in the reactor vessel. The device comprises a first material gas supply pipe configured to supply first material gas to the reactor vessel. The device comprises a second material gas supply pipe configured to supply second material gas, which is to react with the first material gas, to the reactor vessel. The device comprises a particular gas supply pipe having a solid unit arranged on a supply passage. The device comprises a first heater unit configured to heat the solid unit to a predetermined temperature or higher. The solid unit comprises a mother region and a first region arranged continuously within the mother region. The mother region is a region that does not decompose at the predetermined temperature. The first region is a region that decomposes at the predetermined temperature and contains Mg.

A method for preparing an oxygen-free passivated titanium or titanium-alloy powder product by means of gas-solid fluidization is provided. The new method includes placing the metal halide and the titanium powder which meet formula requirements into a gasifier and a fluidized bed reactor respectively; heating the gasifier to gasify the metal halide, and introducing dry argon and halide gas into the fluidized bed reactor; opening the fluidized bed, heating the fluidized bed, fluidizing the titanium powder after the introduction of the argon and the metal halide gas, and cooling the product to obtain the titanium powder subjected to oxygen-free passivation using metal chloride; molding the oxygen-free passivated titanium powder into a green body with powder metallurgy technology; and sintering the green body in vacuum or argon atmosphere according to the molding technology, and after temperature rise treatment, performing a densification sintering operation to obtain a high-performance titanium product component.

A specific type ion source 10 includes a chamber 11; a source gas supply 12 configured to supply an O.sub.2 gas into the chamber 11; a plasma forming device 13 configured to form plasma within the chamber 11 by applying a high frequency power to the O.sub.2 gas supplied into the chamber 11; an accelerator 14 configured to extract ions of an O element included in the plasma formed within the chamber 11 to an outside of the chamber 11, and configured to accelerate the extracted ions in a direction indicated by an arrow AR14; and a sorting device 15 configured to sort out a specific type ion O.sup.− from the ions accelerated by the accelerator 14 and configured to output the sorted specific type ion in a direction indicated by an arrow AR12.

A ceramic matrix composite of the present disclosure includes a fiber substrate including a silicon carbide fiber bundle, and a silicon carbide film formed on a surface of each silicon carbide fiber of the silicon carbide fiber bundle, in which a ratio of an average film thickness D.sub.2 to an average film thickness Di is 1.0 to 1.3, the average film thickness Di being an average film thickness of the silicon carbide film formed on a surface of the silicon carbide fiber in an outer layer of the silicon carbide fiber bundle, and the average film thickness D.sub.2 being an average film thickness of the silicon carbide film formed on a surface of the silicon carbide fiber in an inner layer, which is positioned inside the outer layer, of the silicon carbide fiber bundle.

A method for producing a GaN crystal that includes: (i) a seed crystal preparation step of preparing a GaN seed crystal having one or more facets selected from a {10-10} facet and a {10-1-1} facet; and (ii) a growth step of growing GaN from vapor phase on a surface comprising the one or more facets of the GaN seed crystal using GaCl.sub.3 and NH.sub.3 as raw materials.

A process of preparing polycrystalline group III nitride chunks comprising the steps of (a) placing a group III metal inside a source chamber; (b) flowing a halogen-containing gas over the group III metal to form a group III metal halide; (c) contacting the group III metal halide with a nitrogen-containing gas in a deposition chamber containing a foil, the foil comprising at least one of Mo, W, Ta, Pd, Pt, Ir, or Re; (d) forming a polycrystalline group III nitride layer on the foil within the deposition chamber; (e) removing the polycrystalline group III nitride layer from the foil; and (f) comminuting the polycrystalline group III nitride layer to form the polycrystalline group III nitride chunks, wherein the removing and the comminuting are performed in any order or simultaneously.

Apparatus, systems, and methods for processing workpieces are provided. In one example implementation, a fluorine and oxygen plasma-based process can be used to smooth a roughened surface of a silicon and/or a silicon containing structure. The process can include generating species from a process gas using an inductive coupling element in a first chamber. The process can include introducing a fluorine containing gas and an oxygen containing gas with the species to create a mixture. The process can further include exposing the silicon and/or the silicon containing structure to the mixture such that the mixture at least partially etches a roughened portion to leave a smoother surface of the silicon and/or the silicon containing structure.