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Raman Spectroscopy of Amorphous Carbon Films Modified by Single‐Pulse Irradiation of Nanosecond and Femtosecond Lasers
Author(s) -
Arutyunyan Natalia R.,
Komlenok Maxim S.,
Zavedeev Evgeny V.,
Pimenov Sergei M.
Publication year - 2018
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201700225
Subject(s) - materials science , fluence , raman spectroscopy , irradiation , laser , amorphous carbon , femtosecond , pulse duration , amorphous solid , carbon fibers , nanosecond , analytical chemistry (journal) , absorption (acoustics) , pulsed laser deposition , optics , thin film , nanotechnology , chemistry , composite material , crystallography , physics , chromatography , composite number , nuclear physics
Structural modifications of tetrahedral amorphous carbon (ta‐C) films, caused by single‐pulse laser irradiation, were investigated. Graphitization of the films, content and size of sp 2 carbon clusters were analyzed by means of Raman spectroscopy. It has been shown that pulse duration, as well as laser fluence and wavelength of irradiation, strongly influence the processes of graphitization and ablation of the ta‐C films. In particular, heating of the films by the laser beam leads to formation of sp 2 carbon clusters and their enlargement up to the size of several nanometers. Material transformation to graphitized fraction is much more efficient in case of ns pulse duration. In case of fs pulse duration, such factors as multiphoton absorption and evaporation of over‐heated material from the surface at high laser fluence, shorter time of irradiation, and heat transfer to the inner layers of the film lead to relatively weak graphitization characterized by the maximum size of the sp 2 carbon clusters of about 1 nm.