Reconstructing phase-resolved hysteresis loops from first-order reversal curves

TL;DR

This paper introduces a method to reconstruct phase-resolved hysteresis loops from first-order reversal curves (FORC), enabling detailed magnetic phase analysis and quantitative metrics extraction from complex nanoscale systems.

Contribution

A novel technique to derive phase-specific hysteresis loops from FORC measurements, improving analysis of magnetic phase separation and interactions.

Findings

Accurately reconstructs major hysteresis loops from FORC data.

Provides quantitative magnetic metrics like coercivity and saturation fields.

Demonstrates effectiveness on multiple complex magnetic materials.

Abstract

The first order reversal curve (FORC) method is a magnetometry based technique used to capture nanoscale magnetic phase separation and interactions with macroscopic measurements using minor hysteresis loop analysis. This makes the FORC technique a powerful tool in the analysis of complex systems which cannot be effectively probed using localized techniques. However, recovering quantitative details about the identified phases which can be compared to traditionally measured metrics remains an enigmatic challenge. We demonstrate a technique to reconstruct phase-resolved magnetic hysteresis loops by selectively integrating the measured FORC distribution. From these minor loops, the traditional metrics - including the coercivity and saturation field, and the remanent and saturation magnetization - can be determined. In order to perform this analysis, special consideration must be paid to the accurate quantitative management of the so-called reversible features. This technique is demonstrated on three representative materials systems, high anisotropy FeCuPt thin-films, Fe nanodots, and SmCo/Fe exchange spring magnet films, and shows excellent agreement with the direct measured major loop, as well as the phase separated loops.