Propagation of ultrasonic waves in neptunium monochalcogenides

Publication year: 2011
Source: Applied Acoustics, Volume 72, Issue 10, October 2011, Pages 737-741

Devraj, Singh , D.K., Pandey , D.K., Singh , R.R., Yadav

The ultrasonic attenuation and acoustic coupling constants due to phonon–phonon interaction and thermoelastic relaxation mechanisms have been studied for longitudinal and shear waves in B1 structured neptunium monochalcogenides NpX (X: S, Se, Te) along 〈100〉 direction in the temperature range 100–300K. The second and third order elastic constants (SOEC and TOEC) of the chosen monochalcogenides are also computed for the evaluation of ultrasonic parameters. The ultrasonic attenuation due to phonon–phonon interaction process is predominant over thermoelastic relaxation process in these materials. The ultrasonic attenuation in NpTe has been found lesser than other materials NpS, NpSe and GdY (Y: P, As,…