Biquadratic exchange coupling effect on the magnetic properties of (Fe/Ti) multilayers

TL;DR

This study investigates how biquadratic exchange influences the magnetic properties of Fe/Ti multilayers, revealing the importance of structural imperfections and non-collinear magnetic configurations.

Contribution

It demonstrates the significant role of biquadratic exchange in Fe/Ti multilayers and provides a macrospin model that matches experimental observations.

Findings

Biquadratic exchange affects magnetic hysteresis behavior.

Structural imperfections influence interlayer coupling.

Non-collinear magnetic states are identified through phase diagram analysis.

Abstract

This work explores the static and dynamic magnetic properties of weakly antiferromagnetically coupled Fe/Ti superlattices, emphasizing the link between magnetic behavior and structural characteristics. HRTEM and XRD analyses confirm alternating Fe and Ti layers with rough interfaces, especially in upper layers. Magnetic measurements reveal two-step hysteresis loops and a temperature and thickness-dependent interlayer exchange coupling (IEC). A macrospin model incorporating bilinear and biquadratic coupling reproduces the experimental data and supports a phase diagram analysis identifying non-collinear configurations. The results underscore the impact of structural imperfections and highlight the crucial role of biquadratic exchange in Fe/Ti/Fe multilayers.