Spin-flop Phase in a Honeycomb Antiferromagnet Mn0.84Mg0.16TiO3

The spin-flop phase of a honeycomb antiferromagnet of Mn0.84Mg0.16TiO3 has been studied under magnetic field along normal direction to the honeycomb plane by neutron scattering. With increasing a magnetic field from 0 to 5 T, the inelastic scattering intensity increased by 1.5 times at (1 0 0), where the magnetic structure was found to be coilinear-antiferromagnet with the spin parallel to [1 1 0] direction. The spin direction is consistent with a 1.5 times increase of the inelastic intensity. The negligible energy difference between K and K' points suggests small values for both Dzyaloshinskii-Moriya interaction and bond-dependent symmetric anisotropic exchange interaction in this material.