Figure 9

Kerr microscopy investigation of as-cast Mn₅₅Al₄₅C₂, Mn₅₅Al₄₅C₂(VC)_0.5 and Mn₅₅Al₄₅C₂(VC)₁ alloys. The first row are measurements taken at 0 kA/m, while the second row shows images taken at an applied field of 269 kA/m. In all samples, grains can be identified which can be saturated (marked green) and which cannot be saturated (marked yellow). Row three and four illustrate the domain changes coming from 269 kA/m to 0 kA/m (third row) and coming from -269 kA/m to 0 kA/m (fourth row). As expected the domains in the grains are reversing their orientation (black to white and vice versa), but no obvious pinning sites can be identified. The images are cut-outs of the bigger measurements and represent 90 × 90 µm², i.e. the same size as the MFM images in Fig. 8; the red scale bar illustrates 10 µm.