Fig. 1: Photoinduced sp2-to-sp3 structural transformation process in graphite.
From: Driving forces for ultrafast laser-induced sp2 to sp3 structural transformation in graphite
a Schematic of three-stage ultrafast laser-induced structural transformation in graphite. b Atomic structure of AB stacked graphite used in the non-adiabatic first-principles simulations of ultrafast laser-induced sp2-to-sp3 structural transformation. c Time evolution of the laser field waveform, the interlayer spacing ∆d, the intralayer buckling height ∆z and interlayer sliding angle α of graphite. The α is defined as the angle formed by the carbon pairs located in the same x-y position of adjacent layers with respect to the layer plane. The Gaussian-shaped laser pulse is polarized along the armchair direction of graphite with a field strength of E0 = 0.077 V Å−1 and a fluence of F = 0.905 mJ cm2. The pulse width and the photon energy are 10 fs and 1.55 eV, respectively. The laser field reaches the maximum strength E0 at time t0=16 fs. d Time evolution of the number of interlayer bonds (NIB) formed in the laser-induced sp2-to-sp3 structural transformation process.
