Temperature dependent physical effects of ultrasonic wave in beryllium chalcogenides

Sound velocities and thermal properties of BeX (X=S, Se and Te) alkaline-earth chalcogenides

“…They are also presented in Figure 1. Our obtained values of θD are also in general in good agreement with the majority of other theoretical results [5][6][7][8][9][10], [19], [20]. For BeS compound, our obtained value (628 K) of θD is equal exactly the theoretical value of Ref.…”

“…The calculated values of the longitudinal (vl), transverse (vt) and average (vm) elastic wave velocities of BeX (X=S, Se and Te) semiconductors are presented in table 3 and compared with the available theoretical data [5], [6]. It is seen that, the different values of the average sound velocities obtained in this work are in general in good accordance with the data available in the literature.…”

“…Using the values: 4.865, 5.137 and 5.617 Å [14] of the lattice parameter a for BeS, BeSe and BeTe respectively, our calculated values of the Debye temperature are listed in table 4, and compared with the available theoretical data [5][6][7][8][9][10], [19], [20]. They are also presented in Figure 1.…”

“…For example, for BeSe material, our result is localized between the two values of the Ref. [5] and the Ref. [6].…”

“…They found that the modified Becke Johnson (TB-mBJ) potential improves the band gap as compared to the generalized gradient approximation and in close agreement with the experimental results. The sound velocity and the Debye temperature of BeX (X=S, Se and Te) binary semiconductors are also predicted by means of different approximations [2], [5][6][7][8][9][10]. Dabhi et al [7] have established a systematic theoretical study of structural, mechanical, electronic, vibrational and thermodynamical properties of three Beryllium-monochalcogenides BeX (X=S, Se and Te) binary semiconductors in zinc blende, NiAs and rock salt phases by performing ab initio calculations based on densityfunctional theory.…”