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arXiv · 2410.23199

Magnetic and electronic inhomogeneity in Sm$_{1-x}$Eu$_x$B$_6$

M. Victoria Ale Crivillero·Priscila F. S. Rosa·Z. Fisk·J. Müller·P. Schlottmann·S. Wirth
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Abstract

While SmB$_6$ attracts attention as a possible topological Kondo insulator, EuB$_6$ is known to host magnetic polarons that give rise to large magnetoresistive effects above its ferromagnetic order transition. Here we investigate single crystals of Sm$_{1-x}$Eu$_x$B$_6$ by magnetic and magnetotransport measurements to explore a possible interplay of these two intriguing phenomena, with focus on the Eu-rich substitutions. Sm$_{0.01}$Eu$_{0.99}$B$_6$ exhibits generally similar behavior as EuB$_6$. Interestingly, Sm$_{0.05}$Eu$_{0.95}$B$_6$ combines global antiferromagnetic order with local polaron formation. A pronounced hysteresis is found in the magnetoresistance of Sm$_{0.1}$Eu$_{0.9}$B$_6$ at low temperature ($T=$ 1.9 K) and applied magnetic fields between 2.3 $-$ 3.6 T. The latter is in agreement with a phenomenological model that predicts the stabilization of ferromagnetic polarons with increasing magnetic field within materials with global antiferromagnetic order.

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M. Victoria Ale Crivillero, Priscila F. S. Rosa, Z. Fisk, J. Müller, P. Schlottmann, S. Wirth. 2024-10-30. Magnetic and electronic inhomogeneity in Sm$_{1-x}$Eu$_x$B$_6$. https://arxiv.org/abs/2410.23199

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