Magnetic Scanning Probe Calibration Using Graphene Hall Sensor

Magnetic force microscopy (MFM) offers a unique insight into the nanoscopic scale domain structures of magnetic materials. However, MFM is generally regarded as a qualitative technique and, therefore, requires meticulous calibration of the magnetic scanning probe stray field (B_probe) for quantitative measurements. We present a straightforward calibration of B_probe using scanning gate microscopy on epitaxial graphene Hall sensor in conjunction with Kelvin probe force microscopy feedback loop to eliminate sample-probe parasitic electric field interactions. Using this technique, we determined B_probe ~ 70 mT and ~ 76 mT for probes with nominal magnetic moment ~ 1 × 10^-13 and > 3 × 10^-13 emu, respectively, at a probe-sample distance of 20 nm.