Polycrystalline MnBi as a transverse thermoelectric material

TL;DR

This study evaluates polycrystalline MnBi's potential as a transverse thermoelectric material by measuring its anomalous Nernst effect, demonstrating comparable thermopower to single crystals and highlighting its suitability for thermoelectric applications.

Contribution

The paper experimentally investigates polycrystalline MnBi's anomalous Nernst effect, showing its thermopower is comparable to single crystals, thus advancing its potential as a thermoelectric material.

Findings

Achieved an ANE thermopower of -1.1 μV/K at 1 T in MnBi.

Prepared MnBi samples via powder metallurgy allowing shape and magnetic property customization.

Polycrystalline MnBi exhibits thermoelectric properties comparable to single crystals.

Abstract

To assess the potential of polycrystalline MnBi as a transverse thermoelectric material, we have experimentally investigated its anomalous Nernst effect (ANE) by means of the heat flux method. We prepared MnBi samples by powder metallurgy; this technique allows the preparation of samples in arbitrary shapes with the possibility to tailor their magnetic properties. In the material exhibiting the highest remanent magnetization, we found a value of the ANE thermopower of -1.1 $\mu$V/K at 1 T, after the compensation of the ordinary Nernst effect from pure bismuth present inside the polycrystalline sample. This value is comparable with those reported in the literature for single crystals.