Magnetic Excitations of Spin-Gap System Na3Cu2SbO6 with Distorted Honeycomb Structure

TL;DR

This study investigates the magnetic excitation spectra of Na3Cu2SbO6 with a distorted honeycomb structure, revealing one-dimensional spin chains with alternating ferromagnetic and antiferromagnetic interactions, and quantifying the spin gap and exchange interactions.

Contribution

The paper provides the first neutron inelastic scattering measurements of Na3Cu2SbO6, elucidating its spin chain structure and magnetic interactions, confirming previous macroscopic findings.

Findings

Spin gap of 8.9 meV observed.

Exchange interactions: 13.9 meV (antiferromagnetic), -12.5 meV (ferromagnetic).

Spin system modeled as 1D alternating spin chains.

Abstract

Magnetic excitation spectra of quantum spins of Na3Cu2SbO6 with the distorted honeycomb structure have been measured by neutron inelastic scattering. The intensity distribution and the dispersion curves of the excitations indicate that the spin system can be well understood by considering one-dimensional spin chains formed of Cu2+ ions on a lattice of the alternation of the shorter- and longer-spacings along the b axis. The exchange interactions between the neighboring spins with the shorter- and longer-spacings correspond to ferromagnetic and antiferromagnetic ones, respectively. These findings are consistent with those we reported previously on the basis of macroscopic measurements. The observed spin gap is 8.9 meV and the antiferromagnetic- and ferromagnetic-interactions have been found to be 13.9 and -12.5 meV, respectively.