Numerical computation of magnetic fields applied to magnetic force microscopy

Abstract

Purpose - The purpose of this paper is to introduce a method which allows the calculation of the interactions of tip and sample of a magnetic force microscope as a first step to increase the accuracy of this technique. Design/methodology/approach - The emerging magnetic interactions between the cantilever tip and an arbitrary magnetized sample can be evaluated by the use of several numerical methods. For modelling this magnetically and mechanically coupled multiscale problem the finite element method is implemented. Findings - The evaluated magnetic fields interact in such a manner that a constructive overlap at the tip apex occurs. This leads to attractive forces acting on the cantilever. Research limitations/implications - In order to include the magneto-mechanical coupling, the implementation of a detailed force calculation is necessary. Furthermore, a hysteresis model is not yet considered. Practical implications - Magnetic force microscopy is a very sensitive technique. For instance, ideally the end of the tip consists of only one atom, but this is not realizable. Measurement errors cannot be avoided. This approach is the first step in developing an opportunity to soften them. Originality/value - One opportunity to verify real-time magnetic force microscope measurements is the comparison with theoretical considerations and calculations of the occurring magnetic distribution by using this technique. For this reason this paper deals with a new micromagnetic model to simulate the interactions between tip and sample of a scanning process of a magnetic force microscope. © Emerald Group Publishing Limited.