Elastic properties and optical phonon frequencies of zinc-blende Sc_xGa_1−xN

Abstract

Based on the empirical pseudopotential method within the virtual crystal approximation combined with the Harrison bond-orbital model, the elastic and lattice vibration properties of GaN, ScN and their hypothetical semiconducting alloys Sc x Ga 1−x N in the zinc-blende structure have been investigated. Quantities such as elastic constants, bulk modulus, shear modulus, refractive index, dielectric constants and optical phonon frequencies were calculated as a function of the scandium molar fraction x. The agreement between the present results and the known data that are available only for GaN is generally satisfactory. Our results for Sc x Ga 1−x N (0 < x 1) are predictions.

Trends in the elastic response of binary early transition metal nitrides

“…2 and we will use them in the following analysis for consistency. A comparison with previous DFT-GGA literature data 21,22,40,41,43,44,49 yields, apart from a few exceptions, a good agreement with our results. The local density approximation (LDA) based C 11 elastic constants from the literature 20,42,47 are higher than our GGA-based data.…”

Structure and nanomechanical properties of Al1−xScxN thin films

“…1(a) it can be found that when the films are doped with Sc, the diffraction intensity of (002) peak remarkably decreases and the peak shifts to the low angle side. Generally, the AlN has the wurtzite structure while the ScN has the rock-salt (nonpolar) [21][22][23][24]. When Sc was doped into AlN films, the Sc atoms were substituted on the Al sub-lattice.…”

Optical, Vibrational and Structural Properties of ZnS[sub x]Se[sub 1−x] and CdS[sub x]Se[sub 1−x] alloys

“…These results are utilized further to calculate frequency independent refractive index (n) using Moss relation [7]. The elastic constants c 11 , c 12 , c 44 and bulk modulus B are calculated following the method of Baranowski [8]. The static (H 0 ) and high frequency (H f ) dielectric constants are evaluated combining EPM with Harrison model [8].…”

“…The elastic constants c 11 , c 12 , c 44 and bulk modulus B are calculated following the method of Baranowski [8]. The static (H 0 ) and high frequency (H f ) dielectric constants are evaluated combining EPM with Harrison model [8]. Pressure derivatives of static and high frequency dielectric constants can be obtained as [9]: (1)…”

“…The transverse Z TO (0) and longitudinal Z LO (0) optical phonon frequencies are computed using Lyddane-Sachs-Teller relation and Harrison model [8]. The pressure derivatives of optical phonon frequencies can be deduced by following relations [9]:…”