Local contactless measurement of the ordinary and extraordinary Hall effect using near-field microwave microscopy

We report a polarization-sensitive scanning microwave microscope based on a bimodal dielectric resonator with a cross-slit aperture. The microscope operates at ∼26 GHz in the reflection mode and has a subwavelength spatial resolution. It allows contactless mapping of the conductivity tensor, including magnetic-field-induced terms such as the Hall effect. We demonstrate local contactless measurement of the ordinary Hall effect in semiconducting wafers and of the extraordinary Hall effect in thin ferromagnetic Ni films. The latter yields out-of-plane magnetization. The microwave measurements are in good agreement with the dc Hall-effect measurements.