An acoustic teaching model illustrating the principles of dynamic mode magnetic force microscopy

Mario Reimer, Sybille Niemeier, Daniel Laumann, Cornelia Denz, Stefan Heusler

Abstract

Magnetic force microscopy (MFM) represents a versatile technique within the manifold methods of scanning probe microscopy (SPM), focusing on the investigation of magnetic phenomena at the nanoscale. Although magnetism is a fundamental element of physics education, educational content at the cutting edge of actual scientific topics and techniques in magnetism, like MFM, is lacking. Therefore, we present a scaled teaching model imparting the core principles of MFM, implementing a macroscopic model operating in dynamic mode. The experimental configuration of the model is based on popular bricks by LEGO and drivers based on LEGO Mindstorms (Lego, Billund, Denmark), as well as on further off the shelf components being easily accessible for schools and universities. Investigations of macroscopic magnetic structures reveal numerical, visual and auditory information based on magnetic forces between an oscillating cantilever and ferromagnetic samples allowing a sensual experience of force microscopy for students. Along these lines, students obtain multiple representations to study the precision measurement process of SPM in general and MFM in particular at a scale that allows experiencing micro- and nanoscopic effects. The magnetic force gradients and spatial resolution of the macroscopic model are in agreement with those of an authentic microscopic magnetic force microscope.