Structural,electronic and mechanical properties of alkaline earth metal oxides MO (M=Be,Mg, Ca,Sr, Ba) |
| |
| Institution: | 1. Department of Physics, N.M.S.S.V.N College, Madurai, Tamilnadu 625019, India;2. Department of Physics and Nanotechnology, SRM University, Chennai, Tamilnadu 603203, India;1. College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007, China;2. College of Physics and Electric Information, Luoyang Normal University, Luoyang 471002, China;3. National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900, China;1. Department of Physics, Jamia Millia Islamia, New Delhi, 110025, India;2. Laboratoire de Physique Quantique, de La Matie`re et de La Modélisation Mathématique (LPQ3M), Université de Mascara, Mascara, 29000, Algeria;3. Department of Physics, Islamic University of Science and Technology, Awantipora, Jammu and Kashmir, 192122, India;1. Department of Physics, Manipal Institute of Technology, Manipal University, Manipal 576104, India;2. Microtron Centre, Department of Studies in Physics, Mangalore University, Mangalagangotri 74199, DK, Karnataka, India;3. UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017, India;4. UGC-DAE Consortium for Scientific Research, R5 Shed, Bhabha Atomic Research Centre, Mumbai 400085, India |
| |
| Abstract: | The structural, electronic and mechanical properties of alkaline earth metal oxides MO (M=Be, Mg, Ca, Sr, Ba) in the cubic (B1, B2 and B3) phases and in the wurtzite (B4) phase are investigated using density functional theory calculations as implemented in VASP code. The lattice constants, cohesive energy, bulk modulus, band structures and the density of states are computed. The calculated lattice parameters are in good agreement with the experimental and the other available theoretical results. Electronic structure reveals that all the five alkaline earth metal oxides exhibit semiconducting behavior at zero pressure. The estimated band gaps for the stable wurtzite phase of BeO is 7.2 eV and for the stable cubic NaCl phases of MgO, CaO, SrO and BaO are 4.436 eV, 4.166 eV, 4.013 eV, and 2.274 eV respectively. A pressure induced structural phase transition occurs from wurtzite (B4) to NaCl (B1) phase in BeO at 112.1 GPa and from NaCl (B1) to CsCl (B2) phase in MgO at 514.9 GPa, in CaO at 61.3 GPa, in SrO at 42 GPa and in BaO at 14.5 GPa. The elastic constants are computed at zero and elevated pressures for the B4 and B1 phases for BeO and for the B1 and B2 phases in the case of the other oxides in order to investigate their mechanical stability, anisotropy and hardness. The sound velocities and the Debye temperatures are calculated for all the oxides using the computed elastic constants. |
| |
| Keywords: | Ab-initio calculations Crystal structure Phase transitions Electronic structure Mechanical properties |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
