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.

Sponge-like carbon thin films: The dealloying concept applied to copper/carbon nanocomposite

“…As increasing the Cu content within the films from 61 to 85 at.%, the size of the Cu nanoparticles increases from $5 to $18 nm (Table 1), whereas the thickness of the carbon matrix surrounding the Cu nanoparticles stays almost constant ($2 nm). These results are consistent with most of observations reported in literature for different metal/carbon systems [67][68][69][70][71][72]. The formation of such heterogeneous material is a consequence to the phase separation between copper and carbon on the substrate surface during the growth due to the very low solubility of carbon in copper (evaluated between 4.8 and 7.4 at ppm) [73].…”

One-step topological preparation of carbon doped and coated TiO2 hollow nanocubes for synergistically enhanced visible photodegradation activity

“…31,32 In a typical procedure, 5 mL HF (AR, $ 40%) was slowly added dropwise into 30 mL CH 3 COOH (AR, $ 99.5%) under continuous magnetic stirring. Aer stirring for 0.5 h, the mixed solution was added to a polyvinyl uoride beaker containing 15 g tetrabutyl titanate (TBT, CP, $ 98.0%) to obtain a white emulsion.…”

On the Origin of Reduced Cytotoxicity of Germanium-Doped Diamond-Like Carbon: Role of Top Surface Composition and Bonding

“…As a consequence, a near-surface region of the DLC:Ge samples is partially or fully depleted by Ge. (ii) The C sp 3 /C sp 2 ratio is highly influenced by Ge doping, indicating the dopinginduced structural evolution of carbon atoms hybridizations from sp 3 to sp 2 [9,34]. This is clearly seen in Figure 2a where the dominating C sp 3 contribution in C 1s envelope for the undoped DLC layer G0 transforms step-by-step to the C sp 2 one with increasing Ge content in the Ge-doped DLC layers G1-G5.…”

“…These a main signs of an increasing sp 2 content with Ge doping [22,49], in accord with the angular-resolved X-ray induced photoelectron spectroscopy (ARXPS) data. The C sp 3 to C sp 2 structural evolution is frequently observed for metal-doped layers [9,27,34,50]. Foong et al [34] analysed Cu-doped DLC layers prepared by th deposition method.…”