Remanent states of nanoscale Co ferromagnets having different shapes

The remanent states of 10-nm-thick nano-patterned Co elements were determined using off-axis electron holography. Different types of in-plane magnetic induction distributions were visible depending on the object shape. The remanent states of triangles, squares, pentagons and hexagons were identified as being twisted, whereas those for rectangles, ellipses and dumbbells were basically linear. Elements shaped as disks and rings had remanent states that were essentially circular, whereas slotted disks ("Pacman" shapes) and slotted rings had modified circular remanent states that were highly reproducible and with minimal stray leakage field.