Magnetic properties of the Shastry-Sutherland lattice material BaNd$_2$ZnO$_5$

TL;DR

This study explores the magnetic properties of BaNd$_2$ZnO$_5$, revealing antiferromagnetic order below 1.65 K with a specific 2-Q magnetic structure and detailed crystal field analysis.

Contribution

It provides the first detailed characterization of the magnetic structure and crystal field effects in BaNd$_2$ZnO$_5$, a Shastry-Sutherland lattice material.

Findings

Antiferromagnetic order below 1.65 K

2-Q magnetic structure with moments in the lattice plane

Crystal field ground state doublet well separated at 8 meV

Abstract

We investigate the physical properties of the Shastry-Sutherland lattice material BaNd$_2$ZnO$_5$. Neutron diffraction, magnetic susceptibility, and specific heat measurements reveal antiferromagnetic order below 1.65 K. The magnetic order is found to be a 2-$\boldsymbol{Q}$ magnetic structure with the magnetic moments lying in the Shastry-Sutherland lattice planes comprising the tetragonal crystal structure of BaNd$_2$ZnO$_5$. The ordered moment for this structure is 1.9(1) $\mu_B$ per Nd ion. Inelastic neutron scattering measurements reveal that the crystal field ground state doublet is well separated from the first excited state at 8 meV. The crystal field Hamiltonian is determined through simultaneous refinement of models with both the LS coupling and intermediate coupling approximations to the inelastic neutron scattering and magnetic susceptibility data. The ground state doublet indicates that the magnetic moments lie primarily in the basal plane with magnitude consistent with the size of the determined ordered moment.