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Debye temperature; elastic constants; band gap; first-principles; DFT$+U$

First-principles calculations were performed to study the elastic stiffness constants ($C_{ij}$) and Debye temperature ($\theta_D$) of wurzite (wz) AlN and GaN binary semiconductors at high pressure. The lattice constants were calculated from the optimized structure of these materials. The band gaps were calculated at 𝛤 point using local density approximation (LDA) approach. The unit cell volume, lattice parameters, $c/a$, internal parameter (𝑢), elastic constant ($C_{ij}$), Debye temperature ($\theta_D$), Hubbard parameter (𝑈) and band gap ($E_g$) were studied under different pressures. The bulk modulus ($B_0$), reduced bulk modulus ($B'_0$) and Poisson ratio ($\vee$) were also calculated. The calculated values of these parameters are in fair agreement with the available experimental and reported values.

B P Pandey¹ V Kumar² Eduardo Menendez Proupin³

1. Department of Electronics & Communication Engineering, GLA University, Mathura 281 406, India
2. Department of Electronic Engineering, Indian School of Mines, Dhanbad 826 004, India
3. Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Santiago, Chile

Published

September 2014

Manuscript received

20 October 2013

Manuscript revised

12 January 2014

Accepted

28 January 2014

Early published

5 September 2014