TITLE:
Ultrasonic Attenuation in Calcium Oxide
AUTHORS:
Jitendra Kumar, Kailash R., Sanjeev Kumar Shrivastava, Devraj Singh, Virendra Kumar
KEYWORDS:
Attenuation, Thermo Elastic Relaxation, Phonon-Phonon Interaction, Akheiser Loss, Gruneisen Constants
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.1 No.2,
September
30,
2011
ABSTRACT: Ultrasonic attenuation studies can be used to characterize material not only after production but during processing as well. The most important causes of ultrasonic attenuation in solids are electron-phonon, phonon-phonon interaction and that due to thermo elastic relaxation. The two dominant processes that will give rise to appreciable ultrasonic attenuation at higher temperature are the phonon-phonon interaction also known as Akhiezer loss and that due to thermo elastic relaxation are observed in calcium oxide crystal. At frequencies of ultrasonic range and at higher temperatures in solids, phonon-phonon interaction mechanism is dominating cause for attenuation. Ultrasonic attenuation due to phonon-phonon interaction (α/f2)p-p and thermo elastic relaxation (α/f2)th are evaluated in Calcium Oxide crystal up to an elevated temperature from 100 K - 1500 K along , and crystallographic directions. Temperature dependence of ultrasonic attenuation along different crystallographic direction reveals some typical characteristic features.