On the Structure of Crystalline Graphite Intergrowths

Surface wave propagation in an elastic laser‐excited half‐space with small‐scale effects

“…1 Introduction During the past several years, the characteristics of the vibration and wave propagation in elastic solids (semiconductors and metals) with non-equilibrium atomic defects have been received a lot of attention [1][2][3][4][5][6]. Various structural imperfections in the crystal lattice, i.e., point atomic defects, which are produced from the lattice site atoms due to pulsed laser beam introduce a significant strain of the medium as a result of the difference between the radii of lattice atoms and defects [7], and play an important role in surface modification of solids exposed to laser radiation [7,8]. The formation of defects may occur also in a number of other technologies processes, for examples in the laser fast recrystallization, laser annealing, multipulse laser etching, and pulsed laser-assisted thin-film deposition.…”

“…Examples of such defects are interstitial atoms, vacancies, color centers, and electron-hole pairs. Strains in an elastic wave cause the defects to move within a crystal cell (a strain-induced drift), whereas the strains and a variation in the temperature in the wave modulate the probabilities of generation and recombination of defects of the thermal-fluctuation origin (via variations in the energies of the defect formation and migration) [7,8].…”

“…where h and g are the intrinsic characteristic length scale parameters, characterizing the defect-atom and atom-atom interactions, respectively; r 2 is the Laplacian; b 0 ¼ KV d is the deformation potential of the defect (K ¼ l 0 þ 2m 0 =3 is the bulk elasticity modulus and V d is the change of the volume of the medium due to formation of a single defect [7]). The quantity V d can have different signs, depending on a particular type of defect.…”