Electromagnetic excitation of ultrasound in magnetically ordered dielectrics

The electromagnetic excitation of sound in magnetically ordered dielectrics—ferro-and antiferromagnets—is investigated theoretically. It is shown that sound generation in dielectrics by the Lorentz mechanism (displacement current) is much less efficient than in metals. The magnetoelastic mechanism of sound excitation in dielectrics is just as efficient as in metals. In antiferromagnets the amplitude of the excited sound depends on the relaxation parameter in the magnetic subsystem. The sound excitation efficiency increases as the orientational phase transition point or the ferromagnetic resonance frequency is approached. Zh. éksp. Teor. Fiz. 111, 1810–1816 (May 1997)