A Class of Compounds Featuring Frustrated Triangular Magnetic Lattice CsRESe$_2$ (RE=La-Lu): Quantum Spin-Liquid Candidates

TL;DR

This study synthesizes and characterizes CsRESe2 compounds with frustrated triangular magnetic lattices, identifying potential quantum spin-liquid candidates due to the absence of long-range magnetic order down to very low temperatures.

Contribution

It reports the synthesis and magnetic property analysis of a new series of CsRESe2 compounds, highlighting their potential as quantum spin liquids.

Findings

No long-range magnetic order observed down to 0.4 K.

CsDySe2 shows spin-glass behavior at 0.7 K.

CsCeSe2 and CsYbSe2 exhibit signs of short-range interactions.

Abstract

A triangular lattice selenide series of rare earth (RE), CsRESe2, were synthesized as large single crystals using a flux growth method. This series stabilized in either trigonal (R-3m) or hexagonal (P63/mmc) crystal systems. Physical properties of CsRESe2 were explored by magnetic susceptibility and heat capacity measurements down to 0.4 K. Antiferromagnetic interaction was observed in all magnetic compounds, while no long-range magnetic order was found, indicating the frustrated magnetism. CsDySe2 presents spin freezing at 0.7 K, revealing a spin-glass state. CsCeSe2 and CsYbSe2 present broad peaks at 0.7 K and 1.5 K in the magnetization, respectively, suggesting the short-range interactions between magnetic rare earth ions. The lack of signature for long-range magnetic order and spin freezing down to 0.4 K in these compounds (RE = Ce, Yb) implies their candidacy for quantum spin liquid state.