Crystal Field Levels and Magnetic Anisotropy in the Kagome Compounds $\rm{Nd_3Sb_3Mg_2O_{14}}$, $\rm{Nd_3Sb_3Zn_2O_{14}}$, and $\rm{Pr_3Sb_3Mg_2O_{14}}$

TL;DR

This study determines the crystal field levels and magnetic anisotropy of newly discovered rare-earth kagome compounds using neutron scattering and point-charge models, revealing ground state properties crucial for future research.

Contribution

It introduces a method to accurately determine crystal field Hamiltonians for low-symmetry kagome compounds, providing detailed magnetic ground state insights.

Findings

Nd3Sb3Mg2O14 and Nd3Sb3Zn2O14 have easy-axis doublets

Pr3Sb3Mg2O14 has a singlet ground state

The method accurately reproduces bulk susceptibility data

Abstract

We report the crystal field levels of several newly-discovered rare-earth kagome compounds: $\rm{Nd_3Sb_3Mg_2O_{14}}$, $\rm{Nd_3Sb_3Zn_2O_{14}}$, and $\rm{Pr_3Sb_3Mg_2O_{14}}$. We determine the CEF Hamiltonian by fitting to neutron scattering data using a point-charge Hamiltonian as an intermediate fitting step. The fitted Hamiltonians accurately reproduce bulk susceptibility measurements, and the results indicate easy-axis ground state doublets for $\rm{Nd_3Sb_3Mg_2O_{14}}$ and $\rm{Nd_3Sb_3Zn_2O_{14}}$, and a singlet ground state for $\rm{Pr_3Sb_3Mg_2O_{14}}$. These results provide the groundwork for future investigations of these compounds and a template for CEF analysis of other low-symmetry materials.