Anomalous Nernst effect in stressed magnetostrictive film grown onto flexible substrate

Sci Rep. 2019 Oct 25;9(1):15338. doi: 10.1038/s41598-019-51971-7.

Abstract

The anomalous Nernst effect in nanostructured magnetic materials is a key phenomenon to optimally control and employ the internal energy dissipated in electronic devices, being dependent on, for instance, the magnetic anisotropy of the active element. Thereby, here, we report a theoretical and experimental investigation of the magnetic properties and anomalous Nernst effect in a flexible magnetostrictive film with induced uniaxial magnetic anisotropy and under external stress. Specifically, we calculate the magnetization behavior and the thermoelectric voltage response from a theoretical approach for a planar geometry, with magnetic free energy density that takes into account the induced uniaxial and magnetoelastic anisotropy contributions. Experimentally, we verify modifications of the effective magnetic anisotropy by changing the external stress, and explore the anomalous Nernst effect, a powerful tool to investigate the magnetic properties of magnetostrictive materials. We find quantitative agreement between experiment and numerical calculations, thus elucidating the magnetic behavior and thermoelectric voltage response. Besides, we provide evidence to confirm the validity of the theoretical approach to describe the magnetic properties and anomalous Nernst effect in ferromagnetic magnetostrictive films having uniaxial magnetic anisotropy and submitted to external stress. Hence, the results place flexible magnetostrictive systems as promising candidates for active elements in functionalized touch electronic devices.