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arXiv · 2005.03278

Metamagnetic transitions and anomalous magnetoresistance in EuAg$_4$As$_2$ single crystal

Qinqing Zhu·Liang Li·Zhihua Yang·Zhefeng Lou·Jianhua Du·Jinhu Yang·Bin Chen·Hangdong Wang·Minghu Fang
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Abstract

In this paper, the magnetic and transport properties were systematically studied for EuAg$_4$As$_2$ single crystals, crystallizing in a centrosymmetric trigonal CaCu$_4$P$_2$ type structure. It was confirmed that two magnetic transitions occur at $\textit{T}$$_{N1}$ = 10 K and $\textit{T}$$_{N2}$ = 15 K, respectively. With the increasing field, the two transitions are noticeably driven to lower temperature. At low temperatures, applying a magnetic field in the $\textit{ab}$ plane induces two successive metamagnetic transitions. For both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$, EuAg$_4$As$_2$ shows a positive, unexpected large magnetoresistance (up to 202\%) at low fields below 10 K, and a large negative magnetoresistance (up to -78\%) at high fields/intermediate temperatures. Such anomalous field dependence of magnetoresistance may have potential application in the future magnetic sensors. Finally, the magnetic phase diagrams of EuAg$_{4}$As$_{2}$ were constructed for both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$.

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Qinqing Zhu, Liang Li, Zhihua Yang, Zhefeng Lou, Jianhua Du, Jinhu Yang, Bin Chen, Hangdong Wang, Minghu Fang. 2020-05-07. Metamagnetic transitions and anomalous magnetoresistance in EuAg$_4$As$_2$ single crystal. https://doi.org/10.1007/s11433-020-1629-x

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