Ultrasonic properties of the MgB2 superconductor

The sound velocities of longitudinal and shear waves are measured on a poly crystalline MgB2 superconductor with T-c of 39 K. The specimen used in the experiments is pressed and heated using the MgB2 powder. The elastic moduli , Debye temperature and specific heat at room temperature are obtained base d on sound velocity data. The results indicate that the velocities are much higher than those in the usual materials, while elastic constants remain r easonably soft, which may be due to the high transition temperature of the MgB2 superconductor.