2006 Volume 4 Pages 521-527
In this study, we investigated the covalent materials by using a scanning atom probe (SAP) developed by Nishikawa, et al. SAP relaxes the severe requirement of the extremely sharp and slender shaping of sample for an analysis by conventional atom probe (AP). In the application of AP to non-metallic specimens with a low electron conductivity can be overcome by using pulsed laser beam for excitation. Discrete organic molecules and carbon nanotubes (CNT) were examined. CNTs gave mass spectra of few dominant fragments which reflected its one-dimensional homogeneous structure. Discrete molecules showed their molecular ion peaks in their AP mass spectra, which confirmed the softness of the field ionization process. The molecular ion peak disappeared when titania micro crystal was used as substrate in AP measurement. The change in the fragment pattern suggested the emergence of photocatalytic decomposition of adsorbed molecules on titania by laser irradiation. [DOI: 10.1380/ejssnt.2006.521]
