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arXiv · 1204.6222

Magnetically-driven electronic phase separation in the semimetallic ferromagnet EuB$_6$

P. Das·A. Amyan·J. Brandenburrg·J. Müller·P. Xiong·S. von Molnár·Z. Fisk
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Abstract

From measurements of fluctuation spectroscopy and weak nonlinear transport on the semimetallic ferromagnet EuB$_6$ we find direct evidence for magnetically-driven electronic phase separation consistent with the picture of percolation of magnetic polarons (MP), which form highly conducting magnetically-ordered clusters in a paramagnetic and 'poorly conducting' background. These different parts of the conducting network are probed separately by the noise spectroscopy/nonlinear transport and the conventional linear resistivity. We suggest a comprehensive and 'universal' scenario for the MP percolation, which occurs at a critical magnetization either induced by ferromagnetic order at zero field or externally applied magnetic fields in the paramagentic region.

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P. Das, A. Amyan, J. Brandenburrg, J. Müller, P. Xiong, S. von Molnár, Z. Fisk. 2012-04-27. Magnetically-driven electronic phase separation in the semimetallic ferromagnet EuB$_6$. https://doi.org/10.1103/physrevb.86.184425

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