Dynamics of Discrete Breathers in a Pt3Al Crystal

Resumo

The discrete breathers in a Pt₃Al crystal, which exhibit soft (DB1) and hard (DB2) nonlinearity, are shown to possess a number of principal differences. Unlike an immobile and stable DB1, a DB2 breather is mainly localized on four Al atoms and is stretched along one of the close-packed rows of crystals. On the other hand, DB2 can displace hundreds of nanometers along one of the directions of close packing. Having localized a considerable amount of energy, both DB1 and DB2 breathers slowly emit it during their lifetime. A collision of DB1 and DB2 results in part of their energy being released into the Al sublattice, the larger part lost by DB2 that is destroyed faster than DB1. The DB2 breather can effectively transport the energy throughout the crystal, and a collision of DBs results in its considerable localization in the crystal. A capability of transferring the energy can thus give rise to structural transformations far from the focus of excitation of such localized objects.