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arXiv · 1208.3843

Magnetic property and crystalline electric field effect in ThCr$_2$Si$_2$-type CeNi$_2$As$_2$

Yongkang Luo·Jinke Bao·Chenyi Shen·Jieke Han·Xiaojun Yang·Chen Lv·Yuke Li·Wenhe Jiao·Bingqi Si·Chunmu Feng·Jianhui Dai·Guanghan Cao·Zhu-an Xu
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Abstract

Millimeter sized ThCr$_2$Si$_2$-type CeNi$_2$As$_2$ single crystal was synthesized by NaAs flux method and its physical properties were investigated by magnetization, transport and specific heat measurements. In contrast to the previously reported CaBe$_2$Ge$_2$-type CeNi$_2$As$_2$, the ThCr$_2$Si$_2$-type CeNi$_2$As$_2$ is a highly anisotropic uniaxial antiferromagnet with the transition temperature $T_N$=4.8 K. A field induced spin flop transition was seen below $T_N$ when the applied $\textbf{B}$ is parallel to the $\textbf{c}$-axis, the magnetic easy axis, together with a huge frustration parameter $f=θ_W/T_N$. A pronounced Schottky-like anomaly in specific heat was also found around 160 K, which could be attributed to the crystalline electric field effect with the excitation energies being fitted to $Δ_1=$325 K and $Δ_2=$520 K, respectively. Moreover, the in-plane resistivity anisotropy and low temperature X-ray diffractions suggest that this compound is a rare example exhibiting a possible structure distortion induced by the $4f$-electron magnetic frustration.

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Yongkang Luo, Jinke Bao, Chenyi Shen, Jieke Han, Xiaojun Yang, Chen Lv, Yuke Li, Wenhe Jiao, Bingqi Si, Chunmu Feng, Jianhui Dai, Guanghan Cao, Zhu-an Xu. 2012-12-27. Magnetic property and crystalline electric field effect in ThCr$_2$Si$_2$-type CeNi$_2$As$_2$. https://doi.org/10.1103/physrevb.86.245130

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