Microscale magnetic patterning of hard magnetic films using microfabricated magnetizing masks

We present a batch-fabrication process to imprint microscale magnetic pole patterns (perpendicular north/south poles) into hard magnetic films using field-shaping, soft magnetic “magnetizing masks”. Using 7-μm-thick, electroplated Fe-Co magnetizing masks, magnetic stripes with widths down to 50 μm have been imprinted into both 15-μm-thick Co-Pt films and 5-μm-thick Nd-Fe-B films. These patterned films exhibit a sinusoidal stray magnetic field pattern with ~4 and ~7 mT_pk-pk variations and corresponding field gradients of 80 and 140 T/m, respectively. We also demonstrate the ability to transfer more complex patterns by showing magnetization of various geometric shapes.