Submicronic graphitic particles produced by laser vaporization of a bulk graphite target and sublimated on LiF substrates are investigated. Transmission Electron Microscopy analysis denotes the presence of particles ranging from small clusters to submicronic length scale. Optical absorption and reflectance spectra in the wavelength range from 100 to 2000 nm show that the main contribution to the observed optical features comes from surface plasmon resonance of pi-electrons and from interband transitions of sigma-electrons of the graphite grains. Interferential effects of light due to the granular structure of the films are also present in transmission spectra. Energy shift of the spectral position of the plasmon resonance is observed either in transmission or in reflectance spectra. This shift is due to a size effect of the graphite particles.
"UV SPECTRA OF GRAPHYTE MICROPARTICLES PRODUCED BY LASER VAPORIZATION
CAPOZZI, VITO GIACOMO;
1993-01-01
Abstract
Submicronic graphitic particles produced by laser vaporization of a bulk graphite target and sublimated on LiF substrates are investigated. Transmission Electron Microscopy analysis denotes the presence of particles ranging from small clusters to submicronic length scale. Optical absorption and reflectance spectra in the wavelength range from 100 to 2000 nm show that the main contribution to the observed optical features comes from surface plasmon resonance of pi-electrons and from interband transitions of sigma-electrons of the graphite grains. Interferential effects of light due to the granular structure of the films are also present in transmission spectra. Energy shift of the spectral position of the plasmon resonance is observed either in transmission or in reflectance spectra. This shift is due to a size effect of the graphite particles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
