Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5353257 | Applied Surface Science | 2013 | 5 Pages |
Abstract
Carbon nanostructured materials were obtained by high-repetition rate pulsed laser ablation of a graphite target using a train of 10-ps duration pulses at 1064Â nm in different pressures of high-purity Ar gas. It is demonstrated that their microstructure and optical properties vary as a function of the argon pressure. High-resolution transmission electron microscopy revealed the existence of onion-like carbon nanostructures embedded in a matrix of amorphous carbon nanofoam for samples prepared at 300Â Pa. In comparison samples prepared at 30Â Pa show evidence of both onion-like and turbostratic carbon coexisting in a matrix of amorphous carbon nanofoam whereas samples prepared in vacuum are continuous films of amorphous carbon. Transient transmission spectroscopy measurements suggested that free carrier absorption is the dominant effect following photo-excitation for probing wavelengths in the range of 550-1000Â nm and its magnitude varies among the materials investigated due to their different microstructures.
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Authors
M. Pervolaraki, Ph. Komninou, J. Kioseoglou, A. Othonos, J. Giapintzakis,