Theoretical analysis of magnetic force microscopy contrast in multidomain states of magnetic superlattices with perpendicular anisotropy

TL;DR

This paper provides a theoretical framework for analyzing magnetic force microscopy contrast in multidomain states of magnetic superlattices with perpendicular anisotropy, aiding interpretation of experimental images.

Contribution

It derives analytical equations for stray fields in multidomain states of magnetic multilayers, enhancing understanding of MFM contrast in these systems.

Findings

Closed-form expressions for stray fields in ferromagnetic and antiferromagnetic stripe states.

Theoretical MFM contrast features for realistic tip models.

Application of the theory to experimental data on [Co/Cr]Ru superlattices.

Abstract

Recently synthesized magnetic multilayers with strong perpendicular anisotropy exhibit unique magnetic properties including the formation of specific multidomain states. In particular, antiferromagnetically coupled multilayers own rich phase diagrams that include various multidomain ground states. Analytical equations have been derived for the stray-field components of these multidomain states in perpendicular multilayer systems. In particular, closed expressions for stray fields in the case of ferromagnetic and antiferromagnetic stripes are presented. The theoretical approach provides a basis for the analysis of magnetic force microscopy (MFM) images from this novel class of nanomagnetic systems. Peculiarities of the MFM contrast have been calculated for realistic tip models. These characteristic features in the MFM signals can be employed for the investigations of the different multidomain modes. The obtained results are applied for the analysis of multidomain modes that have been reported earlier in the literature from experiments on [Co/Cr]Ru superlattices.