Multi-Step Magnetic Switching in Single-Crystal (001) Co2MnGe Films

Multistep magnetic switching with single, double, and triple loops has been observed in single-crystal (001) Co 2 MnGe Heusler alloy films epitaxially grown on Gads (001) substrates due to a combined magnetic anisotropy consisting of cubic magnetocrystalline anisotropy and uniaxial anisotropy. Theoretical calculations of the hysteresis loops using coherent rotation show excellent agreement with the experimental results. Domain patterns and magnetization rotation in the Co 2 MnGe films have been studied using the magneto-optical indicator film (MOIF) imaging technique. Magnetic domains and domain walls, as well as the coherent rotation of magnetization in single-step, double-step, and triple-step switching have been clearly observed. The magnetic switching field and domain wall pattern (90° and 180° domain walls) observed from the MOIF images are in excellent agreement with the results of the hysteresis measurements and the theoretical model.