Dynamics of antiferromagnetic vortices in domain wall of yttrium orthoferrite

Summary form only given. Gyroscopic quasi-relativistic dynamics of antiferromagnetic vortices (AFMVs) in the domain wall (DW) of a thin plate of yttrium orthoferrite were investigated by the method of two-fold high-speed photography. The velocities of AFMVs - u were investigated as a function of the DW velocity - v . The u(v) dependence is strongly nonlinear with the maximal value u = 16 km/s at v = 12 km/s, which corresponds to full velocity equal to the limiting c = 20 km/s. After that the AFMV velocity starts to decrease and tends to zero as v /spl rarr/ c. The relationship u/sup 2/ + v/sup 2/ = c/sup 2/ takes place for v /spl ges/ 12 km/s. The full velocity of AFMV w was also studied as a function of the DW velocity u . The velocity w first rises and saturates on the velocity 20 km/s equal to the velocity of spin waves.