Magnetocaloric effect in multilayers studied by membrane-based calorimetry

TL;DR

This study investigates the magnetocaloric effect in multilayer structures with ferromagnetic spacers, demonstrating enhancement over bulk materials through direct calorimetry and modeling of magnetic interactions.

Contribution

It introduces a membrane-based calorimetry method to measure the magnetocaloric effect in multilayers and develops a numerical model to explain the observed enhancement.

Findings

Enhanced magnetocaloric effect in multilayers compared to bulk spacers

Direct measurement of temperature change using nanomembrane calorimetry

Long-range exchange interaction is essential in the model

Abstract

We study magnetic multilayers, incorporating dilute ferromagnetic spacers between strongly-ferromagnetic layers exhibiting a proximity-enhanced magnetocaloric effect. Using magnetometry and direct measurements of the adiabatic temperature change based on a nanomembrane-calorimetry, we find that the magnetocaloric effect in the studied multilayer is indeed enhanced compared to that in the bulk spacer material. We develop a phenomenological numerical model of the studied trilayer and find that a long-range exchange interaction through the weakly-ferromagnetic spacer is required to adequately describe the magnetic and magnetocaloric properties of the system.