Growth of chromium carbide capped-carbon nanotip using bias-assisted microwave plasma chemical vapor deposition

Chromium carbide capped-carbon nanotips were synthesized using bias-assisted microwave plasma chemical vapor deposition. Such a material grew up to several hundreds of nanometer long and tens of nanometer in diameter. The applied bias voltage is a significant parameter in the growth process whereas the higher bias voltage is effective in increasing the growth rate. However, the higher bias voltage also contributes to a rapid formation of chromium carbide which leads to a shorter length of carbon nanotip at the same time. Higher ion energies also vary the tip diameter due to strong ion bombardment which is a competitor to the deposition process. Our investigations revealed that the growth of chromium carbide capped-carbon nanotips reaches a limit due to the full carburization of chromium.