Figure 1

Magnetization hysteresis and zero-field MFM measurements for the three samples used in this work (sample details presented in the main text). (a) Hysteresis curves, in the hard plane (sample plane), normalized by the saturation magnetization Ms of each sample. (b–d) MFM phase maps for samples S1, S2 and S3 respectively. The colour codes the attraction of the magnetic tip (phase signal), and reveals the domain structure. The period is easily determined from such MFM images.