Carbon vacancy ordering in zirconium carbide powder

Synthesis of zirconium carbide nanoparticles by sol-gel method and determination of powder characteristics

In this study, zirconium carbide nanoparticles were synthesized by the sol-gel method in the alcoholic system. The sol was prepared in a three-component alkoxide-water-alcohol system based on the chemical sol-gel process under acidic conditions and at pH = 5. Zirconium n-propoxide, furfuryl alcohol were used as raw materials. After the hydrolysis process and formation of the gel, the initial po...

Equilibrium analysis of zirconium carbide CVD growth

A chemical equilibrium study was performed to investigate the effect of growth parameters on the constitution in ZrC films grown by chemical vapor deposition (CVD). The equilibrium analysis of the Zr–C–H system demonstrated that ZrC (fcc) deposition is favorable and that a certain minimum amount of hydrogen should prevent co-deposition of elemental carbon over a wide range of temperature, press...

In situ hydrogen loading on zirconium powder

For the first time, various hydride phases in a zirconium-hydrogen system have been prepared in a high-energy synchrotron X-ray radiation beamline and their transformation behaviour has been studied in situ. First, the formation and dissolution of hydrides in commercially pure zirconium powder were monitored in real time during hydrogenation and dehydrogenation, then whole pattern crystal struc...

Spin and photophysics of carbon-antisite vacancy defect in 4H silicon carbide: A potential quantum bit

Discovery of carbon-vacancy ordering in Nb4AlC3–x under the guidance of first-principles calculations

The conventional wisdom to tailor the properties of binary transition metal carbides by order-disorder phase transformation has been inapplicable for the machinable ternary carbides (MTCs) due to the absence of ordered phase in bulk sample. Here, the presence of an ordered phase with structural carbon vacancies in Nb4AlC3-x (x ≈ 0.3) ternary carbide is predicted by first-principles calculations...