Hydrogenated amorphous carbon films were irradiated at room temperature both with ion beams and laser pulses. Ion irradiation was performed with 300 keV Ar+ ions at current densities of about 1 muA cm-2 and the average density release was of about 10(24)-10(25) eV cm-3, while laser irradiation was performed with a Ruby laser (0.694 mum) with an energy flow of 0.1-1.2 J cm-2 and an energy release of about 10(22) eV cm-3. The electronic and atomic structure of irradiated layers were investigated by optical measurements in the range 1-6 eV and Raman spectroscopy in the region of C-C stretching modes (1000-2000 cm-1). It was found that laser irradiation shows a stronger efficiency with respect to ion beam bombardment in the modification of the film structure. Moreover Raman spectroscopy shows a progressive growth of the trigonal carbon component with respect to the tetrahedral one with increasing energy deposited inside the sample. The differences between ion and photon energy release mechanisms and a comparison with thermal processes are discussed in terms of primary interaction with the molecular constituents of the samples.
COMPARISON BETWEEN PULSED-LASER AND ION IRRADIATION OF HYDROGENATED AMORPHOUS-CARBON FILMS
COMPAGNINI, Giuseppe Romano;REITANO, Riccardo
1994-01-01
Abstract
Hydrogenated amorphous carbon films were irradiated at room temperature both with ion beams and laser pulses. Ion irradiation was performed with 300 keV Ar+ ions at current densities of about 1 muA cm-2 and the average density release was of about 10(24)-10(25) eV cm-3, while laser irradiation was performed with a Ruby laser (0.694 mum) with an energy flow of 0.1-1.2 J cm-2 and an energy release of about 10(22) eV cm-3. The electronic and atomic structure of irradiated layers were investigated by optical measurements in the range 1-6 eV and Raman spectroscopy in the region of C-C stretching modes (1000-2000 cm-1). It was found that laser irradiation shows a stronger efficiency with respect to ion beam bombardment in the modification of the film structure. Moreover Raman spectroscopy shows a progressive growth of the trigonal carbon component with respect to the tetrahedral one with increasing energy deposited inside the sample. The differences between ion and photon energy release mechanisms and a comparison with thermal processes are discussed in terms of primary interaction with the molecular constituents of the samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
