Analysis of Magnetic Switching Field of Perpendicular/Patterned Media Using in-Field Magnetic Force Microscopy

In this study, the spatial distribution of MSF in CoCrPt-Si02 granular perpendicular recording medium and CoCrPt patterned medium are reported. MFM images were observed with a SPA300HV scanning probe microscope coupled to an electromagnet producing a controllable perpendicular magnetic field of up to 10 kOe in a vacuum. The diameter of the cutting edge of the probe tip was less than 30 nm. Measurement conditions, such as the vibration amplitude of the tip (15 nm for morphology scanning and 3 nm for phase measurement), tip-to-sample distance (~8 nm), and Q factor (~3500) of the cantilever, were carefully selected and controlled so that a resolution of about 15-20 nm could be expected. tial fluctuations of the magnetic switching field. MSF-map