Laser-induced structure transition of diamond-like carbon coated on cemented carbide and formation of reduced graphene oxide

We report on the structural evolution of diamond-like carbon (DLC) films by the nanosecond pulsed laser annealing process. DLC film is coated on cemented carbide (WC-Co) by cathodic arc ion plating, which is then annealed by ArF laser (193 nm, 20 ns) at different laser fluences (0.9-1.7 J/cm(2)). Upon laser annealing, Raman spectra divulge higher sp(3) fractions accompanied by a blue shift in the G-peak position, which indicates the changes of sp(2) sites from rings to chains. At higher fluence (>1.2 J/cm(2)), the film converts into reduced graphene oxide confirmed by its Raman-active vibrational modes: D, G, and 2D.