Elastic and Acoustic Properties of Hexagonal Intermetallic Ternary Compound

The elastic, acoustic and mechanical properties of the hexagonal AlB₂-type intermetallic NdCuGe ternary compound have been studied along unique axis at room temperature. The second- and third order elastic constants have been calculated for NdCuGe compound using Lennard-Jones potential model. The temperature variation of the ultrasonic velocities is evaluated along different angles with unique axis of the crystal using the second order elastic constants. Temperature variation of the thermal relaxation time and Debye average velocities is also calculated along the same orientation. The temperature dependency of the acoustic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of ultrasonic attenuation as a function of temperature and the responsible cause of attenuation is phonon-phonon interaction. The mechanical properties of NdCuGe intermetallic compound at low temperature are better than at room temperature, because at low temperature it has low ultrasonic velocity and ultrasonic attenuation.