External magnetic field effects on a distorted kagome antiferromagnet

TL;DR

This study investigates how an external magnetic field influences the magnetic properties and spin dynamics of a distorted kagome antiferromagnet, Cu_{2}(OD)_3Cl, revealing a canted antiferromagnetic order and modeling its behavior.

Contribution

It introduces a simple spin Hamiltonian with non-uniform exchange interactions and single-ion anisotropy that explains the observed spin dynamics.

Findings

Ordered state below 6.7 K is a canted antiferromagnet

Magnetic field affects spin structure and dynamics

Model reproduces experimental spin behavior

Abstract

We report bulk magnetization, and elastic and inelastic neutron scattering measurements under an external magnetic field, $H$, on the weakly coupled distorted kagome system, Cu_{2}(OD)_3Cl. Our results show that the ordered state below 6.7 K is a canted antiferromagnet and consists of large antiferromagnetic $ac$-components and smaller ferromagnetic $b$-components. By first-principle calculations and linear spin wave analysis, we present a simple spin hamiltonian with non-uniform nearest neighbor exchange interactions resulting in a system of coupled spin trimers with a single-ion anisotropy that can qualitatively reproduce the spin dynamics of Cu_{2}(OD)_3Cl.