Pseudopotential study of barium chalcogenides under hydrostatic pressure

Abstract

We present first-principles calculations within the pseudo-potential plane wave method in the local density approximation (LDA) and the generalised gradient approximation so as to study the structural properties of BaX (X = S, Se and Te) in both NaCl and CsCl structures. The elastic, vibrational properties and lattice dynamics are calculated with the LDA and the density functional perturbation theory. The pressure dependence of the structural, vibrational and lattice dynamics has been investigated by varying the volume. A good agreement is obtained between our calculation and the available experimental and theoretical data.

Extreme pressure conditions of bas based materials: Detailed study of structural changes, band gap engineering, elastic constants and mechanical properties

“…Furthermore, when analysing previous results, one can observe great range of calculated elastic coefficients of barium sulphide modifications. However, our LDA calculations are in a good agreement with previous LDA and molecular dynamics (MD) studies [25,26,32,65,66], while GGA computations are in agreement with corresponding GGA theoretical reports from the literature [26,65].…”

“…We observe that the calculated elastic constants for equilibrium rock-salt and high pressure CsCl modification presented in Fig. 6 and Tables S4 and S5 in [66] the supporting information are in good agreement with the great amount of previous theoretical work. Furthermore, when analysing previous results, one can observe great range of calculated elastic coefficients of barium sulphide modifications.…”

Ab initiocalculations of the structural, electronic, thermodynamic and thermal properties of BaSe1−xTexalloys

“…Moreover, semiconductor alloys also have a significant role in many hi-tech applications, in particular in optoelectronic, photovoltaic and electro-optical devices. Although the binary compounds BaTe and BaSe have been the subject of several experimental [7][8][9][10][11][12] and theoretical studies [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], to our best knowledge the literature contains no experimental study on BaSe 1−x Te x ternary alloys apart from a single theoretical study performed by Lin et al on their structural and electronic properties at 25% and 75% of the alloying composition. That study employed a pseudopotential approach at the level of the Perdew-Wang (PW) local density approximation (LDA) and Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) of the exchangecorrelation functional using a CASTEP computational package [30].…”