Magnetism of Nd$_2$O$_3$ single crystals near the N\'{e}el temperature

TL;DR

This study investigates the magnetic properties of Nd₂O₃ single crystals near their Néel temperature, revealing persistent magnetic excitations, anisotropic magnetization, and insights into frustrated interactions on a triangular lattice.

Contribution

The paper provides detailed neutron scattering and thermodynamic data on Nd₂O₃, highlighting persistent magnetic modes above T_N and the influence of crystal field effects on magnetic anisotropy.

Findings

Long-range antiferromagnetic order below 0.55 K

Magnetic mode at 0.37 meV persists above T_N

Strong anisotropy with easy-plane behavior

Abstract

Single crystals of Nd$_2$O$_3$ were grown and characterized using neutron scattering and thermodynamic measurements. Nd$_2$O$_3$ has long-range antiferromagnetic order below $T_{\rm N}$ = 0.55 K and specific heat measurements have demonstrated that a significant amount of the magnetic entropy is released above $T_{\rm N}$. Inelastic neutron scattering experiments reveal a magnetic mode(s) with little dispersion peaked at $\approx$ 0.37 meV that is of greatest intensity below $T_{\rm N}$ but persists above 2$T_{\rm N}$. This persistence of dynamic correlations is likely related to frustrated interactions associated with the nearly-ideal stacked triangular lattice geometry of $J_{\textrm{eff}}$ = 1/2 spins on Nd$^{3+}$ ions. The magnetization is observed to be strongly anisotropic at all temperatures due to crystal field effects, with easy-plane anisotropy observed. A non-compensated magnetic structure is inferred from the temperature-dependence of the magnetization when a magnetic field of sufficient strength is applied within the basal plane near $T_{\rm N}$, and the evolution of the long-range order is summarized in a temperature-field phase diagram.