Preparation of ferrite-coated MFM cantilevers

Abstract

Ferrite-coated magnetic force microscopy (MFM) cantilevers were prepared for the use with a high-frequency MFM (HF-MFM) setup. The ferrite coatings were fabricated by means of radio frequency (RF) magnetron sputtering directly on the Si surface. Two types of ferrites were employed in this study: NiZnFe 2O 4 spinel and Co 2 Z-type hexaferrite (Ba 3Co 2Fe 24O 41, BCFO). The typical thickness of the coatings was 50 nm. For comparison, ferrite samples on (1 0 0) and (1 1 1)-oriented Si substrates (analogous to the surfaces of the cantilevers) were prepared. Successful HF-MFM imaging was performed with both types of cantilevers using harddisk writer poles as samples. The HF-MFM images obtained by ferrite-coated cantilevers evidently reveal more details of the magnetic field distribution of the writer poles up to the GHz range than conventional CoCr-coated MFM cantilevers.