Nernst power factor and figure of merit in compensated semimetal ScSb

Abstract

Recently, topological semimetals have emerged as strong candidates for solid state thermomagnetic refrigerators due to their enhanced Nernst effect. This enhancement arises from the combined contributions of the Berry curvature induced anomalous Nernst coefficient associated with topological bands and the normal Nernst effect resulting from synergistic electron-hole compensation. Generally, these two effects are intertwined in topological semimetals, making it challenging to evaluate them independently. Here, we report the observation of high Nernst effect in the electron hole compensated semimetal ScSb with topologically trivial electronic band structures. Remarkably, we find a high maximum Nernst power factor of $P{F}_N\sim 35\times 10^{-4}$ W m${}^{-1}$ K${}^{-2}$ in ScSb. The Nernst thermopower ($S_{xy}$) exhibits a peak of $\sim$ 47 $\mu$V/K at 12 K and 14 T, yielding a Nernst figure of merit ($z_N$) of $\sim 28\times 10^{-4}$ K${}^{-1}$. Notably, despite its trivial electronic band structure, both the $P{F}_N$ and $z_N$ values of ScSb are comparable to those observed in topological semimetals with Dirac band dispersions. The origin of the large Nernst signal in ScSb is explained by well compensated electron and hole carriers, through Hall resistivity measurements, angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations.

References in corpus (7)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Colossal Nernst power factor in topological semimetal NbSb${}_2$
• Thermopower and Unconventional Nernst in the Predicted Type-II Weyl Semi-metal WTe${}_2$
• Magnetotransport properties of the topological nodal-line semimetal CaCdSn
• Large Nernst effect and field enhanced transversal ZT in ZrTe5
• Thermopower and thermal conductivity in the Weyl semimetal NbP
• Experimental and theoretical study of the correlated compound YbCdSn: Evidence for large magnetoresistance and mass enhancement

Cited by in corpus (1)

• Large non-saturating Nernst thermopower and magnetoresistance in compensated semimetal ScSb