The magnetic switching process in MBE-grown Co2MnAl Heusler alloy film

• The magnetization switching process in MBE-grown Co2MnAl film is studied by MOKE.
• The complex single, double, and triple jumps are observed experimentally.
• The complex jumping processes are explained based on magnetic domain energetics.
• The hard axis direction is precisely determined experimentally and theoretically.

Single-crystalline Co2MnAl Heusler alloy film has been successfully grown on GaAs (001) substrate by molecular-beam epitaxy (MBE). The complex multistep magnetic switchings with single, double, and triple loops, deriving from the in-plane uniaxial magnetic anisotropy superimposed with a cubic anisotropy, have been observed experimentally. All switching processes are revealed to be mediated by the sweeping of 90° and 180° domain walls, and can be explained successfully based on the domain energetics. Theoretical calculation of hard axis orientation using free energy density shows excellent agreement with the experimental result.