Low energy magnetic excitation spectrum of the unconventional ferromagnet CeRh$_{3}$B$_{2}$

TL;DR

This study investigates the magnetic excitation spectrum of CeRh₃B₂ using inelastic neutron scattering, revealing high exchange interactions along the c-axis, anisotropic magnetic behavior, and the inadequacy of simple multiplet models for its ground state.

Contribution

The paper provides detailed experimental insights into the anisotropic magnetic excitations and exchange interactions in CeRh₃B₂, highlighting the complex nature of its ground state beyond simple models.

Findings

High exchange interaction along the c-axis

Strong out of plane and small in plane anisotropies

Localized magnetism indicated by anisotropic quasielastic scattering

Abstract

The magnetic excitation spectrum of the unconventional ferromagnet CeRh$_{3}$B$_{2}$ was measured by inelastic neutron scattering on single crystal sample in the magnetically ordered and paramagnetic phases. The spin-wave excitation spectrum evidences high exchange interaction along the c-axis about two orders of magnitude higher than the ones in the basal plane of the hexagonal structure. Both strong out of plane and small in plane anisotropies are found. This latter point confirms that considering the $J$=5/2 multiplet alone is not adequate for describing the ground state of CeRh$_{3}$B$_{2}$. Quasielastic scattering measured above $T_{Curie}$ is also strongly anisotropic between the basal plane and the c-axis and suggests localized magnetism.