Z-contrast imaging and electron energy-loss spectroscopy analysis of chromium-doped diamond-like carbon films

Abstract

Metal-doped diamond-like carbon films were produced for the purpose of an electrochemical nanoelectrode. In this study we use Z-contrast scanning transmission electron microscopy to directly observe metal cluster formation and distributions within the chromium-doped carbon films. At low doping (∼6 at. % Cr), Cr is uniformly distributed within the C matrix; at high doping (∼12 at. % Cr), Cr-rich clusters are formed. Analyzing electron energy loss spectroscopy Cr L2,3 white line ratios, we find that the Cr tends to be metallic-like when it is uniformly distributed in the C matrix and carbide-like in the Cr-rich clusters. The carbon is more diamond-like at low doping and more graphite/carbide-like at high doping according to the sp2/sp3 electron percentage measurements.