Berry curvature induced anomalous Hall and Nernst effects in a magnetic nodal line semimetal: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Mn</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mi>ZnC</mml:mi> </mml:mrow> </mml:math>

Abstract

Antiperovskite materials are recognized for potentially hosting a variety of topological surfa ce states. Mn-based antiperovskite ${\mathrm{Mn}}_{3}\mathrm{ZnC}$ is one of the nodal line semimetals that exhibits complex magnetic states with both ferromagnetic and ferrimagnetic order below $\ensuremath{\sim}420$ K and $\ensuremath{\sim}200$ K, respectively. In this work, we report the contribution of Berry curvature to the anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) in ${\mathrm{Mn}}_{3}\mathrm{ZnC}$. The value of anomalous Hall conductivity is found to be $\ensuremath{\sim}175\phantom{\rule{0.28em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1}{\text{cm}}^{\ensuremath{-}1}$ at 2 K, with an intrinsic contribution of $\ensuremath{\sim}57\phantom{\rule{0.28em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1}{\text{cm}}^{\ensuremath{-}1}$. The scaling analysis of the anomalous Hall resistivity suggests that both intrinsic Berry curvature and extrinsic scattering mechanisms contribute to the AHE in the ferrimagnetic state; whereas in the ferromagnetic state, it is governed by the intrinsic Berry curvature mechanism only. In the temperature range $T=2\ensuremath{-}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, the electrical and thermal transport properties indicate a significant contribution of electron--magnon scattering. We demonstrate that the ANE and AHE are commonly related via the Mott's relation. The peak values of the anomalous Nernst coefficient ${S}_{xy}^{A}$ and the anomalous Peltier coefficient ${\ensuremath{\alpha}}_{xy}^{A}$ are $\ensuremath{\sim}0.45\phantom{\rule{0.16em}{0ex}}\textmu{}\text{V/K}$ and $\ensuremath{\sim}0.31\phantom{\rule{0.16em}{0ex}}\mathrm{A}/\mathrm{mK}$, respectively, at a temperature of $\ensuremath{\sim}150\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. Our results indicate that the observed ANE arises from contributions of both extrinsic skew scattering and intrinsic Berry curvature mechanisms.

Topics & Concepts