Excitation of Soliton-Type Waves in Crystals of the A3B 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.