Amorphous nanostructuralization in HOPG by 10(14) W cm(-2) laser

Abstract

This reports provide an amorphous nanostructuralization technique on the surface modification in Highly Oriented Pyrolytic Graphite (HOPG) by using a femtosecond laser. We showed, for the first time, that the surface of HOPG is changed to the amorphous nanostructuralization graphite by using a femtosecond laser-driven compression technique. Our results also suggest that the HOPG surface is changed until the deeper area from the surface by the laser-driven shock wave. A single shot of a femtosecond laser beam (1.27,similar to,1.33x10(14) W cm(-2) in intensity, with 2mm-diameter, and 110 fs in pulse width) is irradiated under the vacuum ambience onto a 2mm-thick of HOPG. The calculated impact pressures on a sample was 8.3 similar to 8.7 GPa. Crystal structure in the HOPG were analyzed using a Raman spectroscopy and an X-ray diffraction, those analyzing depth from the surface were 50 nm and 350pm, respectively.