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arXiv · 1911.12268

Synthesis, magnetization and heat capacity of triangular lattice materials NaErSe$_2$ and KErSe$_2$

Jie Xing·Liurukara D. Sanjeewa·Jungsoo Kim·William R. Meier·Andrew F. May·Qiang Zheng·Radu Custelcean·G. R. Stewart·Athena S. Sefat
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Abstract

In this paper we report the synthesis, magnetization and heat capacity of the frustrated magnets \emph{A}ErSe$_2$(\emph{A}=Na,K) which contain perfect triangular lattices of Er$^{3+}$. The magnetization data suggests no long-range magnetic order exists in \emph{A}ErSe$_2$(\emph{A}=Na,K), which is consistent with the heat capacity measurements. Large anisotropy is observed between the magnetization within the \emph{ab} plane and along the \emph{c} axis of both compounds. When the magnetic field is applied along \emph{ab} plane, anomalies are observed at 1.8 $\mu_B$ in NaErSe$_2$ at 0.2 T and 2.1 $\mu_B$ in KErSe$_2$ at 0.18 T. Unlike NaErSe$_2$, a plateau-like field-induced metamagnetic transition is observed for H$\|$\emph{c} below 1 K in KErSe$_2$. Two broad peaks are observed in the heat capacity below 10 K indicating possible crystal electric field(CEF) effects and magnetic entropy released under different magnetic fields. All results indicate that \emph{A}ErSe$_2$ are strongly anisotropic, frustrated magnets with field-induced transition at low temperature. The lack of signatures for long-range magnetic order implies that these materials are candidates for hosting a quantum spin liquid ground state.

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Jie Xing, Liurukara D. Sanjeewa, Jungsoo Kim, William R. Meier, Andrew F. May, Qiang Zheng, Radu Custelcean, G. R. Stewart, Athena S. Sefat. 2019-11-27. Synthesis, magnetization and heat capacity of triangular lattice materials NaErSe$_2$ and KErSe$_2$. https://doi.org/10.1103/physrevmaterials.3.114413

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