Ceramics-Silikáty 55, (2) 127 - 133 (2011)

Higher order elastic constants have been calculated in hexagonal structured ceramic material TiB₂ at temperature dependent following the interaction potential model. The temperature variation of the ultrasonic velocities is evaluated along different angles with z axis (unique axis) of the crystal using the second order elastic constants. The ultrasonic velocity decreases with the temperature along particular orientation with the unique axis. Temperature variation of the thermal relaxation time and Debye average velocities is also calculated along the same orientation. The temperature dependency of the ultrasonic 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.