Excitation of soliton-type waves in crystals of the A$_{3}$B stoichiometry

Using the method of molecular dynamics and taking Ni$_{3}$Al and Pt$_{3}$Al as examples, crystals of the A$_{3}$B composition are considered for the possibility of excitation of soliton-type waves in them. The potentials obtained by the embedded-atom method were used to describe interatomic interactions. It is shown that the harmonic external stimulus can excite waves of the soliton type in a Pt$_{3}$Al crystal, but not in Ni$_{3}$Al. Such compression–expansion waves are generated because of excitation of discrete breathers with soft nonlinearity that cannot exist in a Ni$_{3}$Al crystal near the affected region. The detected waves are capable of propagating to thousands of nanometers along the Pt$_{3}$Al crystal without losses of integrity and speed. The shape of the obtained wave corresponds to the kink solution of the sine-Gordon equation. The aggregate amount of energy transferred by a wave is determined by the number of rows of atoms involved in fluctuations; this may involve dozens and hundreds of electron volts.