Point defects in crystals of the Pt–Al system: energy characteristics and interaction with solitary waves in nonlinear supratransmission

10.25712/ASTU.1811-1416.2026.03.007

Abstract

Real crystals invariably contain point defects; however, their interaction with solitary waves of nonlinear supratransmission—specifically, the scattering of waves by defects and the ability of these waves to initiate defect migration—has remained quantitatively uncharacterized. Using atomistic modeling, we investigate the energetic characteristics of point defects in the face‑centered cubic (FCC) metals Pt and Al, along with their interaction with solitary waves excited in the intermetallic compound Pt₃Al under the nonlinear supratransmission regime. Within the framework of a unified interatomic potential constructed via the embedded‑atom method (EAM), we compute the formation energies of vacancies and self‑interstitial atoms in the ⟨100⟩ dumbbell configuration. Vacancy migration barriers are determined using the nudged elastic band (NEB) method and compared with reference data. The interaction of solitary waves with defects is examined in a series of sixteen molecular‑dynamics (MD) runs, comprising three types of point defects and a defect‑free control case, each driven at  four driving amplitudes, from threshold to above-threshold. It is established that point defects are virtually transparent to solitary waves: the transmission coefficient differs from the defect‑free case by no more than one percent. Nevertheless, the defect traps a fraction of the energy carried by the wave. The magnitude of the single‑event trapping depends on the defect type; it is largest for a Pt vacancy and amounts to a few hundredths of an electron volt, which is substantially below the corresponding migration barriers. We conclude that multiple or resonant exposures are required for solitary waves to induce a rearrangement of the defect subsystem. These results are applicable to the analysis of energy transport in ordered alloys under intense external driving.