  For submicron particles shaped as any axisymmetric body and made with
standard canted antiferromagnet like hematite or iron borate, the ground state
may comprise of a magnetic vortex with topologically non-trivial distribution
of the sublattice magnetization $\vec{l}$ and planar coreless vortex-like
structure for the net magnetization $\vec{M}$. For antiferromagnetic particles
in the vortex state, in addition to low-frequency modes, there are high
frequency modes with frequencies over the range of hundreds gigahertz,
including a mode localized in the region of the radius 30-40 nm near a vortex
core.
