A Ti/Pt/Co multilayer stack for transfer function based magnetic force microscopy calibrations

TL;DR

This paper introduces a Ti/Pt/Co multilayer stack as a reliable reference for calibrating magnetic force microscopy, enabling accurate quantitative measurements of magnetic structures through well-characterized stray fields.

Contribution

It presents a precisely fabricated Ti/Pt/Co multilayer with a stripe domain pattern as a new reference sample for MFM calibration, validated by micromagnetic simulations and measurements.

Findings

The multilayer stack shows a stable stripe domain pattern.

Good agreement between simulations and experimental data.

Calibrated MFM measurements demonstrate improved quantification.

Abstract

Magnetic force microscopy is a widespread technique for imaging magnetic structures with a resolution of some 10 nanometers. MFM can be calibrated to obtain quantitative spatially resolved magnetization data in units of A/m by determining the calibrated point spread function of the instrument, its instrument calibration function (ICF), from a measurement of a well-known reference sample. Beyond quantifying the MFM data, a deconvolution of the MFM image data with the ICF also corrects the smearing caused by the finite width of the MFM tip stray field distribution. However, the quality of the calibration depends critically on the calculability of the magnetization distribution of the reference sample. Here, we discuss a Ti/Pt/Co multilayer stack that shows a stripe domain pattern as a suitable reference material. A precise control of the fabrication process, combined with a characterization of the sample micromagnetic parameters, allows reliable calculation of the sample's magnetic stray field, proven by a very good agreement between micromagnetic simulations and qMFM measurements. A calibrated qMFM measurement using the Ti/Pt/Co stack as a reference sample is shown and validated, and the application area for quantitative MFM measurements calibrated with the Ti/Pt/Co stack is discussed