Investigation of one-dimensional nonlinear vibrational model in FCC aluminum


It is known that the nonlinearity of interatomic interactions can ensure the existence of spatially localized vibrational modes in the crystal lattice. In the present work, we investigate a one-dimensional nonlinear vibrational mode of a new type in a defect-free FCC single crystal. In this mode, the atoms of one close-packed series oscillate with the same amplitude in antiphase with the nearest neighbors. The amplitudes of atomic vibrations in neighboring close-packed chains are much smaller and decrease rapidly with distance from the excited chain. The considered vibrational mode can be classified as a discrete breather (DB) of a special form, in which the oscillations are localized in two spatial directions and are delocalized in the third direction (along a close-packed atomic row). The obtained results broaden our understanding of the nonlinear dynamics of the crystal lattice of FCC metals