High coercive magnetic force microscopy probes by cobalt ferrite

Magnetic force microscope (MFM) is one of the most convenient analytical tools to detect the near-surface stray-field variation in magnetic films. Probes for MFM are normally prepared by coating magnetic materials onto silicon probes. With the application of MFM for characterize hard magnetic materials, it is strongly recommended that the sensitive part must be magnetically hard to avoid the magnetization reversal by the stray field from the detection films. Films with high magnetic anisotropy, such as FePt, CoPt have been proposed as magnetically hard coatings. In this study, we show our results on prepare cobalt ferrite films with high coercivity for MFM probes. A special process is developed to deposit cobalt ferrite with coercivities larger than 10 kOe also keep the apex sharpness.