Synthesis and anisotropic magnetism in quantum spin liquid candidates AYbSe2 (A = K and Rb)

Jie Xing,Andrew F May,Athena S Sefat,Liurukara D Sanjeewa

doi:10.1063/5.0071161

Jie Xing, Andrew F May + Show 2 more

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https://doi.org/10.1063/5.0071161

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Abstract

The quantum spin liquid (QSL) state in rare-earth triangular lattices has attracted much attention recently due to its potential application in quantum computing and communication. Here, we report the single-crystal growth synthesis, crystal structure characterizations, and magnetic properties of AYbSe2 (A = K and Rb) compounds. The x-ray diffraction analysis shows that AYbSe2 (A = K and Rb) crystallizes in a trigonal space group, R-3m (No. 166) with Z = 3. AYbSe2 possesses a two-dimensional (2D) Yb–Se–Yb layered structure formed by edged-shared YbSe6 octahedra. The magnetic properties are highly anisotropic for both title compounds, and no long-range order is found down to 0.4 K, revealing the possible QSL ground state in these compounds. The isothermal magnetization exhibits a one-third magnetization plateau when the magnetic fields are applied in the ab-plane. Heat capacity is performed along both ab-plane and c axis and features the characteristic dome for triangular magnetic lattice compounds as a function of magnetic fields. Due to the change in the interlayer and intralayer distance of Yb3+, the dome shifts to low fields from KYbSe2 to RbYbSe2. All these results indicate that the AYbSe2 family presents unique frustrated magnetism close to the possible QSL and noncollinear spin states.

Highlights

INTRODUCTIONSince Mg2+ and Ga3+ have two different charges, this can affect the crystal electric field splitting of the Yb3+ site compared to the perfect structure
Single crystal x-ray structure investigation reveals that both KYbSe2 and RbYbSe2 adopt the trigonal R-3m space group compared to P63/mmc in CsYbSe2
The crystal structure is built from 2D Se–Yb–Se layers where A-site cations reside in between the layers. These 2D Se–Yb–Se layers are packed along the c axis as displayed in Fig. 2; the packing of Se–Yb–Se layers and A-site cations is different between the R-3m and P63/mmc space groups

Summary

INTRODUCTION

Since Mg2+ and Ga3+ have two different charges, this can affect the crystal electric field splitting of the Yb3+ site compared to the perfect structure This type of intrinsic Mg/Ga disorder between the Yb3+ layers could perturb the spin liquid ground state.. Our INS on CsYbSe2 single crystals suggests that this system could provide a natural realization of the QSL ground state.59 For this purpose, we extend our study to investigate the structure–property correlation of KYbSe2 and RbYbSe2. The magnetization and heat capacity are performed down to 0.4 K when the applied magnetic field is along the ab-plane and c axis Both KYbSe2 and RbYbSe2 do not exhibit long-range ordering above 0.4 K, suggesting the QSL ground state.

EXPERIMENTAL SECTION

Crystal structure

CONCLUSION