  In this work we have used focused electron beam induced deposition of cobalt
to functionalize atomic force microscopy Akiyama tips for application in
magnetic force microscopy. The grown tips have a content of 90% Co after
exposure to ambient air. The magnetic tips were characterized using energy
dispersive X-ray spectroscopy and scanning electron microscopy. In order to
investigate the magnetic properties, current loops were prepared by electron
beam lithography. Measurements at room temperature as well as 4.2K were carried
out and the coercive field of 68 Oe of the Co tip was estimated by applying
several external fields in the opposite direction of the tip magnetization.
Magnetic Akiyama tips open new possibilities for low to room-temperature
magnetic force microscopy measurements.
