In situ compensation method for high-precision and high-sensitivity integral magnetometry

TL;DR

This paper introduces an in situ magnetic compensation method to enhance the sensitivity and accuracy of SQUID magnetometry for small magnetic samples, reducing interference from carriers and system noise.

Contribution

The paper presents a universal, easy-to-implement in situ compensation technique that improves SQUID magnetometry without complex modeling, applicable across various materials and sample types.

Findings

Effective suppression of carrier and support signals in magnetometry.

Improved measurement accuracy for small magnetic samples.

Method applicable to emerging materials like topological insulators.

Abstract

An ongoing process of miniaturization of spintronics and magnetic-films-based devices, as well as a growing necessity for basic material research place stringent requirements for sensitive and accurate magnetometric measurements of minute magnetic constituencies deposited on large magnetically responsive carriers. However, the most popular multipurpose commercial superconducting quantum interference device (SQUID) magnetometers are not object-selective probes, so the sought signal is usually buried in the magnetic response of the carrier, contaminated by signals from the sample support, system instabilities and additionally degraded by an inadequate data reduction. In this report a comprehensive method based on the in situ magnetic compensation for mitigating all these weak elements of SQUID-based magnetometry is presented. Practical solutions and proper expressions to evaluate the final outcome of the investigations are given. Their universal form allows to employ the suggested design in investigations of a broad range of specimens of different sizes, shapes and compositions. The method does not require any extensive numerical modelling, it relies only on the data taken from the standard magnetometer output. The solution can be straightforwardly implemented in every field where magnetic investigations are of a prime importance, including in particular emerging new fields of topological insulators, 3D-Dirac semimetals and 2D-materials.