Three-dimensional Sandglass Magnet with Non-Kramers ions

TL;DR

This study investigates the magnetic properties of a newly synthesized three-dimensional Tm$_3$SbO$_7$ lattice with non-Kramers ions, revealing low-temperature behavior explained by a transverse field Ising model and highlighting the role of different Tm$^{3+}$ ions.

Contribution

It introduces a new 3D sandglass lattice with non-Kramers ions and demonstrates how its low-energy properties are governed by a transverse field Ising model supported by experimental data.

Findings

Absence of magnetic order or glassy state down to 0.1 K.

Low-temperature behavior explained by a transverse field Ising model.

Perturbations from Tm$^{3+}_2$ influence spin dynamics.

Abstract

Magnetic susceptibility, specific heat, and muon spin relaxation ($\mu$SR) measurements have been performed on a newly synthesized three-dimensional sandglass-type lattice Tm$_3$SbO$_7$, where two inequivalent sets of non-Kramers Tm$^{3+}$ ions (Tm$^{3+}_1$ and Tm$^{3+}_2)$ show crystal electrical field effect at different temperature ranges. The existence of an ordered or a glassy state down to 0.1~K in zero field is excluded. The low-energy properties of Tm$_3$SbO$_7$ are dominated by the lowest non-Kramers quasi-doublet of $\rm Tm^{3+}_1$, and the energy splitting is regarded as an intrinsic transverse field. Therefore, the low-temperature paramagnetic phenomenon in Tm$_3$SbO$_7$ is explained by a transverse field Ising model, which is supported by the quantitative simulation of specific heat data. In addition, the perturbation from Tm$^{3+}_2$ may play an important role in accounting for the low temperature spin dynamics behavior observed by $\mu$SR.