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.