SmCo-based MFM probes with high switching fields

MFM probes with high switching fields have been synthesized by depositing Cr/SmCo₅/Cr trilayers onto commercial Si AFM probes. The maximum switching field values of the probes (between 4 T and 5 T for probes annealed at 550 °C for 5 min) is lower than the coercivity measured on similar trilayers (6.8 T) deposited on a Si substrate. Reducing the annealing time of the probes results in a lower switching field while increasing the annealing time leads to a drop in the magnetization of the probes. Such ultra-high switching field MFM probes are of interest for characterizing a range of materials including hard magnetic materials in the remanent state or under an external applied magnetic field and magnetic transducers under excitation.