Scaling of High-Frequency Sound Propagation near the Ferromagnetic Transition of MnP

The propagation of longitudinal sound waves at frequencies between 10 and 520 MHz is analyzed at the ferromagnetic transition of metallic MnP. In spite of the existence of highly asymmetric attenuation about $T_c$, it is shown that the data are consistent with a symmetric critical relaxation time, $\tau$. It is also shown that the reduced attenuation can be scaled by functions of $\omega \tau$ which differ above and below $T_c$.