The sound velocities of longitudinal and shear waves were measured in polycrystalline samples with TC = 39K. The specimens used were pressed and heated using MgB2 powder. The elastic moduli, Debye temperature and specific heat at room temperature were obtained, based upon sound velocity data. The results indicated that the velocities were much higher than those in other materials, while the elastic constants remain reasonably soft. This was perhaps due to the high transition temperature of the superconductor.

Ultrasonic Properties of the MgB2 Superconductor. S.C.Li, R.J.Wang, F.Y.Li, Z.X.Liu, J.L.Zhu, R.C.Yu, C.Q.Jin: Chinese Physics Letters, 2001, 18, 1369-70