X-ray photoemission electron microscopy studies of local magnetization in Py antidot array thin films

Permalloy antidot thin films were grown by sputtering onto anodic alumina templates, replicating their hexagonal order inside micrometrie geometric domains. The advanced high-spatial and sensitive x-ray photoemission electron microscopy technique under an applied magnetic field has enabled magnetic domain structure imaging and quantitative hysteresis loop analysis inside nanoscale regions with geometric order and at border regions. The study has been complemented by vibrating sample magnetometry and magneto-optic Kerr effect measurements. The magnetization process is clearly determined by the geometry characteristics of the antidot arrays. Inside geometric ordered domains, the strength of effective in-plane magnetic anisotropy depends on the antidot diameter-to-film thickness ratio, which determines the partial balance between stray fields generated by magnetic charges at the lateral surface of the antidots and those at the upper- bottom film surface. In addition, the border regions between geometric domains act as pinning centers for magnetization reversal and eventually generate a harder magnetic region.