Effect of bismuth crystal orientations in Nernst thermomagnetic devices

TL;DR

This study investigates how the orientation of bismuth crystals affects the Nernst effect, revealing anisotropic behavior crucial for designing efficient thermomagnetic energy harvesters.

Contribution

It provides detailed measurements of the Nernst coefficient in single crystal bismuth along different orientations, highlighting the importance of crystal orientation in thermomagnetic device performance.

Findings

Significant anisotropy in Nernst coefficient based on crystal orientation

Correlation between electronic structure anisotropy and thermomagnetic response

Implications for optimizing thermomagnetic device design

Abstract

In this work we report Nernst effect measurements in single crystal bismuth samples, with special emphasis on the characterization of the Nernst coefficient when the magnetic field, heat current and generated voltage are aligned along specific directions relative to the crystal axes. We found significant differences between the different orientations, reflecting the highly anisotropic electronic structure of bismuth and compatible with the Nernst characteristics obtained from polycrystalline samples. These results not only complement the experimental works published in the past but also underline the role of crystalline orientation in the context of transverse thermoelectric effects, towards an efficient design of thermomagnetic devices like the ordinary-Nernst-effect-based energy harvesters.