Spin Waves in the Ferromagnetic Ground State of the Kagome Staircase System Co3V2O8

TL;DR

This study investigates spin wave excitations in the ferromagnetic ground state of Co3V2O8 using inelastic neutron scattering, revealing complex magnetic interactions and the applicability of linear spin-wave theory.

Contribution

It provides detailed experimental insights into the magnetic excitations of Co3V2O8, highlighting the spin-wave behavior and magnetic exchange interactions in the kagome staircase system.

Findings

Two spin-wave branches observed

Finite spin-wave lifetimes below Tc

Negligible exchange coupling between spine sites

Abstract

Inelastic neutron scattering measurements were performed on single crystal Co3V2O8 wherein magnetic cobalt ions reside on distinct spine and cross-tie sites within kagome staircase planes. This system displays a rich magnetic phase diagram which culminates in a ferromagnetic ground state below Tc~6 K. We have studied the low-lying magnetic excitations in this phase within the kagome plane. Despite the complexity of the system at higher temperatures, linear spin-wave theory describes most of the quantitative detail of the inelastic neutron measurements. Our results show two spin-wave branches, the higher energy of which displays finite spin-wave lifetimes well below Tc, and negligible magnetic exchange coupling between Co moments on the spine sites.