Browsing by Author "Jasieniak, M"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Characterisation of methane plasma treated carbon surfaces
    (Institute of Electrical and Electronics Engineers, 2008-02-25) Deslandes, A; Jasieniak, M; Ionescu, M; Shapter, JG; Quinton, JS
    Time of Flight Secondary ion Mass Spectrometry (ToF-SIMS) was used to investigate the chemical nature of methane plasma treated graphite surfaces. Principle Component Analysis (PCA) was applied to the SIMS data, revealing chemical changes to the surfaces, in particular the extent of hydrogenation. The hydrogen content of the HOPG surface is observed to increase with systematic increases in power of the plasma treatment. These results are supported by Elastic Recoil Detection Analysis (ERDA) measurements that show a similar increase in hydrogen content. Scanning Tunneling Microscopy (STM) measurements provide insight into the morphological changes to the surface caused by the treatment, via investigating plasma-created features that are observed to increase in coverage with the increases in plasma power. © 2008 IEEE.
  • No Thumbnail Available
    Item
    Hydrogenation of sp(2)-bonded carbon surfaces using methane plasma
    (Elsevier, 2010-01-01) Deslandes, A; Jasieniak, M; Ionescu, M; Shapter, JG; Quinton, JS
    Highly ordered pyrolytic graphite was exposed to radio-frequency methane plasma to produce a hydrogen-terminated carbon surface. The effects of treatment parameters, namely exposure time, applied power and methane pressure, upon the treated surfaces’ chemical and morphological properties were systematically investigated. Scanning tunnelling microscopy measurements showed growth features on the plasma treated surface, the coverage of which was shown to increase with plasma exposure time or applied plasma power and decrease with gas pressure. Analyses of post-treated surface structures (via static secondary ion mass spectrometry with the aid of principle component analysis) showed an increase in surface hydrogen with plasma exposure time, applied plasma power and decreasing gas pressure. The results of these analyses were further supported by elastic recoil detection analysis measurements, which showed similar trends for the experimental parameters on the resultant surface hydrogen content. © 2010, Elsevier Ltd.
  • No Thumbnail Available
    Item
    ToF-SIMS characterisation of methane- and hydrogen-plasma-modified graphite using principal component analysis.
    (Wiley-Blackwell, 2009-03) Deslandes, A; Jasieniak, M; Ionescu, M; Shapter, JG; Fairman, C; Gooding, JJ; Hibbert, DB; Quinton, JS
    Time of flight secondary ion mass spectrometry (ToF-SIMS) has been used to determine the extent of surface modification of highly ordered pyrolytic graphite (HOPG) samples that were exposed to radio-frequency methane and hydrogen plasmas. The ToF-SIMS measurements were examined with the multivariate method of principal component analysis (PCA), to maximise the amount of spectral information retained in the analysis. This revealed that the plasma (methane or hydrogen plasma) modified HOPG exhibited greater hydrogen content than the pristine HOPG. The hydrogen content trends observed from the ToF-SIMS studies were also observed in elastic recoil detection analysis measurements. The application of the ToF-SIMS PCA method also showed that small hydrocarbon fragments were sputtered from the hydrogen-plasma-treated sample, characteristic of the formation of a plasma-damaged surface, whereas the methane-plasma-treated surface sputtered larger hydrocarbon fragments, which implies the growth of a polymer-like coating. Scanning tunnelling microscopy measurements of the modified surfaces showed surface features that are attributable to either etching or film growth after exposure to the hydrogen or methane plasma. © 2009, Wiley-Blackwell.