A co-reduction synthesis of superconducting NbC nanorods

Abstract

NbC nanorods with diameters of 50-150 nm were successfully synthesized through a new chemical route by using NbCl 5 and hexachlorobutadiene (C 4 Cl 6 ) as Nb and C sources, and Na metal as the reductant at 600 • C in an autoclave. This reaction temperature is much lower than that used in traditional methods. The as-prepared NbC nanorods were characterized by x-ray powder diffraction, transmission electron microscopy and x-ray photoelectron spectra. Magnetization measurement indicated that the NbC nanorods have a superconducting transition at 12.3 K.

High critical field NbC superconductor on carbon spheres

“…The measurement was performed in step mode with a step size of 0.02 and a stepping time of 8 s. For the quantitative phase analysis of the composite sample, the PXRD data was analysed by the Java based MAUD program. 11,22 The isotropic size (d XRD ) for NbC was calculated to be 60 nm from the refinement process. The microstructure of the sample was further studied using a transmission electron microscope (TEM) (JEM 2100, JEOL) operated at 200 kV.…”

“…It is found to be particularly useful in hot-electron bolometric superconducting mixtures 1 and in superconducting radio-frequency (SCRF) cavities. 6,7 Although, since its discovery in 1964, 8 significant research attention has been paid to improve its superconducting properties 1,[9][10][11] by various techniques, it is currently the least studied superconductor in the literature. [3][4][5] However, due to the wide range of homogeneity of intermixing (NbC 1.0 to NbC 0.72 ), the cell parameters (a) and the superconducting transition temperature (T c ) of NbC are usually found to depend strongly on the carbon content.…”

pH‐Responsive Microrods Produced by Electric‐Field‐Induced Aggregation of Colloidal Particles

“…String-length distributions were obtained from image analysis (ImageJ v1.31v). For each size distribution, several images were used, covering a total area of over 1 mm 2 . After creating binary images, the maximum Ferret's diameter was measured for each aggregate over 3 lm.…”

“…rods, [2] to solar cells, [3] sensors, [4] and gene therapy. [5] Much research has focused on metallic and semiconductor rods less than 50 nm in length because of their useful optical and electronic properties.…”

A thermal reduction route to nanocrystalline transition metal carbides from waste polytetrafluoroethylene and metal oxides

“…For example, NbC is not only a catalyst but also a superconducting material [2], VC and Mo 2 C are powerful catalysts and considered potential substitutes of noble metals in catalysis [3,4], and TiC can be used for anti-wear coating on cutting tools [5]. Various methods for the synthesis of transition metal carbides have been reported, such as direct carbonization of metal [6e8], chemical vapor deposition [9,10], carbothermal reduction of metal oxides with carbon at high temperature [11e13], solid state metathesis [14,15], a thermal reduction of metal oxides and carbonate with Mg [16], and coreduction of metal halides and C x Cl y with sodium [17]. Metal oxides are more chemically stable, cheaper, and more common in nature compared with metal halides.…”