Unraveling the role of the magnetic anisotropy on thermoelectric response: a theoretical and experimental approach

TL;DR

This paper combines theoretical modeling and experimental validation to investigate how magnetic anisotropies influence the thermoelectric response in ferromagnetic systems, revealing new insights into the manipulation of ANE and LSSE effects.

Contribution

It introduces a modified Stoner-Wohlfarth model to analyze the impact of different magnetic anisotropies on thermoelectric behavior, validated by experimental data.

Findings

Magnetic anisotropies significantly alter thermoelectric responses.

Theoretical model accurately predicts experimental thermoelectric curves.

Energy contributions to thermoelectric effects are identified and characterized.

Abstract

Magnetic anisotropies have key role to taylor magnetic behavior in ferromagnetic systems. Further, they are also essential elements to manipulate the thermoelectric response in Anomalous Nernst (ANE) and Longitudinal Spin Seebeck systems (LSSE). We propose here a theoretical approach and explore the role of magnetic anisotropies on the magnetization and thermoelectric response of noninteracting multidomain ferromagnetic systems. The magnetic behavior and the thermoelectric curves are calculated from a modified Stoner Wohlfarth model for an isotropic system, a uniaxial magnetic one, as well as for a system having a mixture of uniaxial and cubic magnetocrystalline magnetic anisotropies. It is verified remarkable modifications of the magnetic behavior with the anisotropy and it is shown that the thermoelectric response is strongly affected by these changes. Further, the fingerprints of the energy contributions to the thermoelectric response are disclosed. To test the robustness of our theoretical approach, we engineer films having the specific magnetic properties and compare directly experimental data with theoretical results. Thus, experimental evidence is provided to confirm the validity of our theoretical approach. The results go beyond the traditional reports focusing on magnetically saturated films and show how the thermoelectric effect behaves during the whole magnetization curve. Our findings reveal a promising way to explore the ANE and LSSE effects as a powerful tool to study magnetic anisotropies, as well as to employ systems with magnetic anisotropy as sensing or elements in technological applications.