Magnetic force microscopy (MFM) allows detection of stray magnetic fields around magnetic materials and the two-dimensional visualization of these fields. This paper presents a theoretical analysis of the oscillations of an MFM tip above a thin film of nonmagnetic metal. The results show good agreement with experimental data obtained by varying the tip height. The phenomenon analyzed here can be applied as a "metal detector" at the nanometer scale and for contactless measurement of sheet resistivity. The detection sensitivity is obtained as a function of oscillation frequency, thus allowing determination of the best frequency for phase-shift measurement. The shift in resonance frequency due to the presence of a nonmagnetic metal is also discussed.
@article{arxiv.1812.03270,
title = {Detection of nonmagnetic metal thin film using magnetic force microscopy},
author = {Fujio Wakaya and Kenta Oosawa and Masahiro Kajiwara and Satoshi Abo and Mikio Takai},
journal= {arXiv preprint arXiv:1812.03270},
year = {2018}
}