Laser ablation electrical conductivity

For the case of both electrically conducting and electrically non-conducting samples, laser ablation combined with AAS may be useful. In this case AAS measurements can be performed directly at the laser plume. Measurement of the non-element specific absorption will be very important, because of the presence of particles, molecules and radicals as well as due to the emission of continuum radiation. In addition, the absorption measurements should be made in the apprppriate zones. When applying laser ablation for direct solids sampling, the atomic vapor produced can also be led into a flame for AAS work, as has previously been described by Kantor et al. [299] in their early work. 

Carbon nanotubes are one-dimensional carbon nanostructures with tubular morphology. Depending on the number of walls present in carbon nanotubes, these are named as single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), and multi-walled carbon nanotubes (MWNTs). Each of these types have slightly different properties. For example, the electrical conductivity of pure SWNT is higher than that of DWNT and MWNT. Carbon nanotubes can be synthesized by arc discharge [11], laser ablation [12], catalytic CVD [13,14], etc. 

Laser Ablation. Laser ablation involves removing material from a surface (usually a solid but occasionally a liquid). Pulsed laser is most commonly used however, at a high intensity, continuous laser can ablate material. At lower levels of laser energy, the material is heated and evaporates. At higher levels, the material is converted to plasma. Plasma is similar to gas, but it differs from gas in that some of the particles are ionized (a loss of electrons). Because of this ionization, plasma is electrically conductive. 

The interaction of the radiation from high-power laser sources with solids can lead to evaporation. As this is independent of the electrical conductivity of the sample, laser ablation is increasingly important for solid analysis [140]-[142]. 

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