Quantitative magnetic force microscopy on permalloy dots using an iron filled carbon nanotube probe

► A Fe-filled carbon nanotube (FeCNT) probe offers compelling advantages for quantitative MFM. ► A FeCNT magnetic probe tip is accurately described as a magnetic monopole. ► The monopole model of the FeCNT magnetic probe has been experimentally validated. ► We present quantitative MFM measurements with 40 nm spatial resolution using a FeCNT probe.