Electronic, Structural and Elastic properties of MgO Based on GGA-mBJ and LDA-mBJ

This work is a comparative study of structural, electronic and elastic MgO oxide properties. The computations are based on density functional theory (DFT)1 by using the full potential linearized augmented plane wave methods ( FP-LAPW)2. For exchange and correlation potential, two approximations are utilized : the local density and the generalized gradient with its four types. The structural parameters such as lattice constant (a) Bulk modulus (B) and its derivative (B’) are calculated using LDA and GGA approximations3. This is realized in the NaCl (B1) structure. The compound is stable in non magnetic phase (paramagnetic). The electronic properties are calculated using the Becke and Johnson modified Local Density and Generalized Gradient approximations (mBJ-LDA and mBJ-GGA). It showed that MgO oxide is an insulator material with direct band gap 7,55 ev (mBJ-LDA). The use of the modified Becke-Johnson potentials as a correlation allowed us to have energy gaps in good agreement with the experimental results. Analysis and values of elastic parameters such as : Young’s modulus E(Gpa), the shear moduls G(Gpa), B/G ration , poisson’s ration, anisotropic factor (A) show that MgO is anisotropic nature. The study of mechanical properties indicate that the compound is mechanically stable and brittle. The theoretical results are in good agreement with the experimental and theoretical work found in the literature.