Nonlinear Absorption of Radio Waves in a Noncollinear Antiferromagnet
The nonlinear absorption of radio waves (200 - 800 MHz) in a noncollinear cubic antiferromagnet Mn3Al2Ge3O12 in an external magnetic field H || [001] has been studied in the temperature range of 1.2 - 4.2 K. We attribute the observed dissipation of the electromagnetic energy to the parametric excitation of inhomogeneous surface waves at the boundaries of antiferromagnetic domains.