The interaction of vanadium oxide and niobium oxide with A1203 and TiO2 supports is examined with Raman spectroscopy. The Raman spectra of the supported metal oxides reveal that the strong interaction of the metal oxides with AI203 and TiO2 supports results in the formation of two-dimensional surface metal oxide overlayers. The surface vanadium oxide overlayers are unstable to high calcination ...

In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typica...

Niobium (Nb)-based alloys have been extensively used in the aerospace field owing to their excellent high-temperature mechanical properties. However, inferior oxidation resistance severely limits application of Nb-based a high-temperature, oxygen-enriched environment. Related scholars studied protection niobium alloy and pointed out that surface coating technology is ideal for solving this prob...

The promoting effect of niobium in a Li/MgO catalyst for the oxidative coupling of methane (OCM) and for the oxidattve dehydrogenation of ethane (ODHE) has been studied in some detail. it has been found that a Li/Nb/MgO catalyst with 16 wt % niobium showed the highest activity for the C, production in the OCM reaction; the activity at 600 “C was ten times that of the Li/MgO catalyst at the same...

Measurements at 8.6 GHz on TM mode superconducting niobium cavities have been carried out at SLAC in an attempt to establish definitive conditions for reproducibly attaining high peak electric and magnetic fields and high residual &Is. Four cavities, processed by techniques which insure thepresence of an oxi& layer on the niobium surface before final high temperature outgassing, have given peak...

Graphite is widely used in technology because of its unique properties. A drawback of graphite is its low heat resistance in oxidizing atmospheres. To increase its heat resistance, Nb-Hf protective coatings were synthesized. Electrodeposition of niobium coatings on graphite with subsequent precise surface alloying of niobium with hafnium was studied. Electrochemical synthesis of Nb-Hf coatings ...