High-frequency MFM characterization of magnetic recording writer poles

By means of high-frequency magnetic force microscopy (HF-MFM), different magnetic recording writer poles are characterized in the frequency range 200-1500 MHz using the dual-vibrational HF-MFM technique. The stray fields emanating from hard disk writer poles stemming from different makers are compared to each other, and the field distributions obtained at different carrier frequencies are analysed. At low carrier frequencies, the maximum field is located directly at the gap, whereas at high frequencies two distinct maxima before and after the gap are observed.