Mechanism behind the surface evolution and microstructure changes of laser fabricated nanostructured carbon composite

Abstract

Many studies have shown that amorphous carbon films with reduced internal stress, improved adhesion strength, and diversified material properties are obtainable through doping process, but the presence of dopants was reported to promote surface evolution and alter the microstructures of carbon matrix. By combining analyses from experimental results and theoretical estimations, this work examines the mechanism behind the surface evolution and microstructural changes in laser fabricated nanostructured copper-carbon composite. We showed that the presence of metal ions during laser deposition increased the heat dissipation on carbon matrix, which enhanced the formation of nanoislands but graphitized the carbon matrix. In addition, theoretical estimations and XPS hinted that the presence of energetic species may force the carbon ions to react with the substrate interface and form silicon carbide bonds, which contributed to the improved adhesion strength observed in copper doped carbon films, along with a reduction in internal stress owing to the presence of nanoclusters. © 2011 American Institute of Physics.