Ultrahigh Coercivity Magnetic Force Microscopy Probes to Analyze High-Moment Magnetic Structures and Devices

This letter addresses the fabrication and exploitation of ultrahigh coercivity magnetic force microscopy (MFM) probes to characterize high-magnetic moment nanostructures and devices. The
$\hbox{L1}_{0}$
phase of FePt alloys together with CrRu and MgO seed layers are investigated as a method of increasing the coercivity of MFM probes to prevent their behavior as soft magnetic probes when used to image energized magnetic devices. The newly developed MFM probes, with coercivity higher than 11 kOe, are utilized to successfully analyze a modern perpendicular magnetic recording write head under various excitation conditions in order to perform writer saturation and remanence tests. The results include MFM micrographs of a fully energized magnetic writer, obtained with a probe-sample separation of only 10 nm.