A manganese carbide (Mn.sub.4C) magnetic material and a production method therefor are provided. According to one embodiment, the saturation magnetization of the Mn.sub.4C magnetic material increases with increasing temperature, and thus the Mn.sub.4C magnetic material is applicable to fields in which thermally induced magnetization reduction is critical.

A cobalt carbide-based catalyst for direct production of olefin from synthesis gas, a preparation method therefor and application thereof are disclosed. The method for preparing the catalyst comprises the following steps: 1) mixing a cobalt source with water, or mixing a cobalt source, an electron promoter and water to obtain a first solution; and mixing a precipitant with water to obtain a second solution; 2) adding the first solution and the second solution to water, or water and a structure promoter for precipitation, crystallizing, separating, drying and calcination; and 3) reducing a solid obtained in Step 2) in a reducing atmosphere, and then carbonizing in a carbonizing atmosphere. The prepared catalyst has high activity and high selectivity to olefins for direct production of olefins via syngas conversion.

A cobalt carbide-based catalyst for direct production of olefin from synthesis gas, a preparation method therefor and application thereof are disclosed. The method for preparing the catalyst comprises the following steps: 1) mixing a cobalt source with water, or mixing a cobalt source, an electron promoter and water to obtain a first solution; and mixing a precipitant with water to obtain a second solution; 2) adding the first solution and the second solution to water, or water and a structure promoter for precipitation, crystallizing, separating, drying and calcination; and 3) reducing a solid obtained in Step 2) in a reducing atmosphere, and then carbonizing in a carbonizing atmosphere. The prepared catalyst has high activity and high selectivity to olefins for direct production of olefins via syngas conversion.

A multi-composition fiber is provided including a primary fiber material and an elemental additive material deposited on grain boundaries between adjacent crystalline domains of the primary fiber material. A method of making a multi-composition fiber is also provided, which includes providing a precursor laden environment, and promoting fiber growth using laser heating. The precursor laden environment includes a primary precursor material and an elemental precursor material.

A multi-composition fiber is provided including a primary fiber material and an elemental additive material deposited on grain boundaries between adjacent crystalline domains of the primary fiber material. A method of making a multi-composition fiber is also provided, which includes providing a precursor laden environment, and promoting fiber growth using laser heating. The precursor laden environment includes a primary precursor material and an elemental precursor material.

Provided herein is a method for preparing MXenes, such as Ti.sub.2CT.sub.x, Cr.sub.2CT.sub.x, and V.sub.2CT.sub.x, products prepared therefrom, and compositions and devices including the same.

Provided herein is a method for preparing MXenes, such as Ti.sub.2CT.sub.x, Cr.sub.2CT.sub.x, and V.sub.2CT.sub.x, products prepared therefrom, and compositions and devices including the same.

The purpose of the present invention is to provide an emitter that is made of hafnium carbide (Hf) and that releases electrons in a stable and highly efficient manner, a method for manufacturing the emitter, and an electron gun and electronic device in which the emitter is used.

In this nanowire-equipped emitter, the nanowires are made of hafnium carbide (HfC) single crystal, the longitudinal direction of the nanowires match the <100> crystal direction of the hafnium carbide single crystal, and the end part of the nanowires through which electrons are to be released comprise the (200) face and the {310} face of the hafnium carbide single crystal, with the (200) face being the center and the {311} face surrounding the (200) face.

The purpose of the present invention is to provide an emitter that is made of hafnium carbide (Hf) and that releases electrons in a stable and highly efficient manner, a method for manufacturing the emitter, and an electron gun and electronic device in which the emitter is used.

In this nanowire-equipped emitter, the nanowires are made of hafnium carbide (HfC) single crystal, the longitudinal direction of the nanowires match the <100> crystal direction of the hafnium carbide single crystal, and the end part of the nanowires through which electrons are to be released comprise the (200) face and the {310} face of the hafnium carbide single crystal, with the (200) face being the center and the {311} face surrounding the (200) face.

Disclosed herein are structures comprising a titanium, zirconium, or hafnium powder particle with titanium carbide, zirconium carbide, or hafnium carbide (respectively) nano-whiskers grown directly from and anchored to the powder particle. Also disclosed are methods for fabrication of such structures, involving heating the powder particles and exposing the particles to an organic gas.