Batch Patterning of SubMillimeter Features in Hard Magnetic Films Using Pulsed Magnetic Fields and Soft Magnetizing Heads

In this paper, we report a method to impart spatially defined magnetic patterns into hard magnetic films using pulsed magnetic fields. Differing from prior investigations on magnetic patterning, a single magnetizing head is used rather than a sandwich structure with two magnetizing heads. Arrays of 250μm-wide and 125μm-wide magnetic stripes with alternating out-of-plane polarity (perpendicular magnetization) are patterned in a 10μm-thick Co-rich Co-Pt alloy (Co₈₀Pt₂₀) film using three different microstructured, 2-mm-thick, Fe-Co magnetizing heads and pulsed magnetic fields ranging from 0.1 to 1 T. A magneto-optical imaging film is used to view the magnetization patterns at the surface of the Co-Pt film. Scanning Hall probe measurements of the resulting magnetic structures indicate a ~5mT peak magnetic field 100 m above the surface which compares favorably with numerical simulations of the field patterns at the same height.