High-frequency magnetic-force microscopy characterization of magnetic recording writer poles

Measurements of longitudinal writer poles at the air bearing surface were performed using high-resolution magnetic-force microscopy (MFM) with low coercivity tips. Two-dimensional MFM maps were obtained for various write currents. The modeling results indicate that the MFM maps are related more to the field than to its second derivative. Two techniques were used, dc MFM and high-frequency (HF) MFM. The results show that the HF-MFM technique can distinguish between different writer designs. The writers with the best high-frequency performance showed gradual decrease of the maximum MFM signal with frequency up to 1.5 GHz. (c) 2005 American Institute of Physics.