Muon Spin Relaxation Study of frustrated Tm${}_3$Sb${}_3$Mg${}_2$O${}_{14}$ with kagomé lattice

Abstract

The structure and magnetic properties of rare-earth ions Tm${}^{3+}$ kagomé lattice Tm${}_3$Sb${}_3$Mg${}_2$O${}_{14}$ are studied by X-ray diffraction, magnetic susceptibility and muon spin relaxation ($\mu$SR) experiments. The existence of a small amount of Tm/Mg site-mixing disorder is revealed. DC magnetic susceptibility measurement shows that Tm${}^{3+}$ magnetic moments are antiferromagnetically correlated with a negative Curie-Weiss temperature of -26.3 K. Neither long-range magnetic order nor spin-glass transition is observed by DC and AC magnetic susceptibility, and confirmed by $\mu$SR experiment down to 0.1 K. However, the emergence of short-range magnetic order is indicated by the zero-field $\mu$SR experiments, and the absence of spin dynamics at low temperatures is evidenced by the longitudinal-field $\mu$SR technique. Compared with the results of Tm${}_3$Sb${}_3$Zn${}_2$O${}_{14}$, another Tm-based kagomé lattice with much more site-mixing disorder, the gapless spin liquid like behaviors in Tm${}_3$Sb${}_3$Zn${}_2$O${}_{14}$ can be induced by disorder effect. Samples with perfect geometrical frustration are in urgent demand to establish whether QSL exits in this kind of materials with rare-earth kagomé lattice.