Ultrasonic attenuation due to polarization domain relaxation processes in the transverse spin density wave phase of antiferromagnetic chromium

Measurements of the field dependence of the ultrasonic attenuation of longitudinal sound waves in the frequency range 10 MHz to 300 MHz propagating in the transverse spin density wave phase of a single Q single crystal of chromium interpreted in terms of a relaxation model for thermally activated polarization domains and provide an independent indication that their volume in this sample is of the order of 10 -15 to 10 -16 cm 3 .