Pressure Tuning the Mixture of Eu$^{2+}$ and Eu$^{3+}$ in Eu$_4$Bi$_6$Se$_{13}$

Mingyu Xu; Jose L. Gonzalez Jimenez; Greeshma C. Jose; Artittaya Boonkird; Chengkun Xing; Chelsea Harrod; Xinle Li; Haidong Zhou; Alyssa Gaiser; Xianglin Ke; Wenli Bi; Mingda Li; Weiwei Xie

arXiv · 2407.00163

Pressure Tuning the Mixture of Eu$^{2+}$ and Eu$^{3+}$ in Eu$_4$Bi$_6$Se$_{13}$

Mingyu Xu·Jose L. Gonzalez Jimenez·Greeshma C. Jose·Artittaya Boonkird·Chengkun Xing·Chelsea Harrod·Xinle Li·Haidong Zhou·Alyssa Gaiser·Xianglin Ke·Wenli Bi·Mingda Li·Weiwei Xie

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Abstract

The investigation of crystallographic, electronic, and magnetic characteristics, especially the mixed valences of Eu$^{2+}$ and Eu$^{3+}$ under pressure of a novel europium-based bismuth selenide compound, Eu$_4$Bi$_6$Se$_{13}$, presented. This new compound adopts a monoclinic crystal structure classified under the P$2_1$/m space group (#11). It exhibits distinctive structural features, including substantial Eu-Se coordination numbers, Bi-Se ladders, and linear chains of Eu atoms that propagate along the b-axis. Electronic resistivity assessments indicate that Eu$_{4}$Bi$_{6}$Se$_{13}$ exhibits weak metallic behaviors. Magnetic characterization reveals uniaxial magnetic anisotropy, with a notable spin transition at approximately 1.2 T when the magnetic field is oriented along the b-axis. This behavior, coupled with the specific Eu-Eu interatomic distances and the magnetic saturation observed at low fields, supports the identification of metamagnetic properties attributable to the flipping of europium spins. The Curie-Weiss analysis of the magnetic susceptibility measured both perpendicular and parallel to the b-axis and high-pressure partial fluorescence yield (PFY) results detected by X-ray absorption spectroscopy (XAS) reveal the tendency of the material to enter a mixed valent state where the trivalent state becomes more prominent with the pressure increase or temperature decrease.

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Mingyu Xu, Jose L. Gonzalez Jimenez, Greeshma C. Jose, Artittaya Boonkird, Chengkun Xing, Chelsea Harrod, Xinle Li, Haidong Zhou, Alyssa Gaiser, Xianglin Ke, Wenli Bi, Mingda Li, Weiwei Xie. 2024-06-28. Pressure Tuning the Mixture of Eu$^{2+}$ and Eu$^{3+}$ in Eu$_4$Bi$_6$Se$_{13}$. https://arxiv.org/abs/2407.00163

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