Coexistence of anomalous spin dynamics and weak magnetic order in a chiral trillium lattice K2FeSn(PO4)3

Abstract

Trillium lattices, where magnetic ions form a three-dimensional chiral network of corner-sharing equilateral triangular motifs, offer a prominent platform to explore exotic quantum states. In this work, we report ground-state properties of the $S$ = 5/2 trillium lattice compound K${}_2$FeSn(PO${}_4$)${}_3$ through thermodynamic, electron spin resonance (ESR), and muon spin relaxation ($\mu$SR) experiments. Thermodynamic and ESR measurements reveal the two-step evolution of magnetic correlations across $T^{\ast }$ = 11 K, which results from an interplay between dominant antiferromagnetic Heisenberg interactions and subleading interactions. Below $T^{\ast }$, \textit{dc} and \textit{ac} magnetic susceptibilities indicate weak \textcolor{black}{magnetic ordering} at $T_{\mathrm{N}}\approx 2$ K under low fields, which is suppressed for ${\mu }_{0}H\ge 2$ T, consistent with a power-law dependence of magnetic specific heat at low temperatures. $\mu$SR experiments confirm the dominance of persistent spin dynamics and the absence of conventional spin freezing, supporting the subtle nature of weak magnetic ordering coexisting with spin-liquid-like fluctuations. These findings underscore the potential for realizing a classical spin-liquid ground state with exotic excitations in high-spin trillium lattice systems.

References in corpus (5)

• Experimental signatures of quantum and topological states in frustrated magnetism
• Magnetic field induced quantum spin liquid in the two coupled trillium lattices of K${}_2$Ni${}_2$(SO${}_4$)${}_3$
• Fate of partial order on the trillium and distorted windmill lattices
• Quantum criticality in the coupled two-leg spin ladder Ba2CuTeO6
• Chiral spin liquid and quantum phase diagram of spin-$1/2$ $J_1$-$J_2$-$J_{\chi }$ model on the square lattice

Cited by in corpus (1)

• Frustration and chirality in three-dimensional trillium lattices: Insights and Perspectives