Magnetoelastic coupling in paramagnetic dysprosium
Kale, Billy Michael
Donoho, Paul L.
Master of Arts
The magnetic field dependence of the velocities of 2 MHz longitudinal acoustic waves has been measured in the temperature range 18K-3K for fields from -17.65 kOe. By choosing the propagation axis to be the b- or c-axis, the field dependence of the elastic constants and is obtainable. Corrections for the magnetostrictive effects, necessary for a consistent treatment of the problem, are included in the analysis. The resulting values of AC(H,T) and LC(RfT), in conjunction with the theoretical work of Southern and Goodings, allows calculation of five of the magnetoelastic constants of Dysprosium in the paramagnetic region. The temperature dependence of these magnetoelastic constants is examined, in the light of the theory, and is compared to that temperature dependence of the same five magnetoelastic constants, of Terbium, found by Salama, Melcher, and Donoho.