Using inelastic neutron scattering, we investigate the spin wave excitations on the antiferromagnetic MnTiO3 (TN = 65 K), which has the stacked honeycomb structure. At T = 2 K, the spin wave energy extends up to 10.7 meV with the zone-center anisotropy gap of 0.8 meV. Whereas the dispersion is also strong along the direction perpendicular to the honeycomb planes, the exchange cancellation causes the magnetic interactions to be effectively anisotropic below TN. While the spin wave spectrum survives at temperatures above TN, we find that the magnetic interactions become more anisotropic within the paramagnetic phase.
ASJC Scopus subject areas
- Physics and Astronomy(all)