Electrical control of fast ordering process in as-deposited non-perpendicular and perpendicular FePt films

Here, DC power supplies were applied on as-deposited non-perpendicular FePt single films or perpendicular FePt/Au multilayer films to control momentum exchanges between rapid moving electrons and Fe or Pt atoms. Moreover, lattice defects in the films provide abundant diffusion pathways for atomic rearrangement. Through the current driven atomic motion and rearrangement, fast LOP and hard magnet properties were realized in the FePt alloy films without heat treatment. The electromigration effect appears to be general and is applicable for the ordering in other magnetic materials with a L10 structure.

► Electrical control of L10 phase transition in FePt film was realized in 45 s.
► Above fast L10 ordering phase transformation does not need any heat treatment.
► Magnetic properties of the FePt film can be tunable by electromigration effect.
► The mechanism relies on electromigration effect and lattice defects in the film.
► The finding is general and shall be applicable for other L10 structured materials.