English

Nernst power factor and figure of merit in compensated semimetal ScSb

Materials Science 2025-07-29 v1 Other Condensed Matter

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 PFN35×104PF_N \sim 35 \times 10^{-4} W m1^{-1} K2^{-2} in ScSb. The Nernst thermopower (SxyS_{xy}) exhibits a peak of \sim 47 μ\muV/K at 12 K and 14 T, yielding a Nernst figure of merit (zNz_N) of 28×104\sim 28 \times 10^{-4} K1^{-1}. Notably, despite its trivial electronic band structure, both the PFNPF_N and zNz_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.

Keywords

Cite

@article{arxiv.2504.15450,
  title  = {Nernst power factor and figure of merit in compensated semimetal ScSb},
  author = {Antu Laha and Sarah Paone and Asish K. Kundu and Juntao Yao and Niraj Aryal and Elio Vescovo and Qiang Li},
  journal= {arXiv preprint arXiv:2504.15450},
  year   = {2025}
}