Iron filled carbon nanotubes as novel monopole-like sensors for quantitative magnetic forcemicroscopy

Abstract

We present a novel ultrahigh stability sensor for quantitative magnetic force microscopy(MFM) based on an iron filled carbon nanotube. In contrast to the complex magneticstructure of conventional MFM probes, this sensor constitutes a nanomagnet with definedproperties. The long iron nanowire can be regarded as an extended dipole of which only themonopole close to the sample surface is involved in the imaging process. We demonstrateits potential for high resolution imaging. Moreover, we present an easy routine to determineits monopole moment and prove that this calibration, unlike other approaches, isuniversally applicable. For the first time this enables straightforward quantitative MFMmeasurements.