Understanding the influences of Mg doping on the physical properties of SrMoO3 perovskite

• Main Authors: Khandaker Monower Hossain, Md. Zahid Hasan, Md. Lokman Ali
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Results in Physics
• Subjects: Structural properties; Mechanical properties; Electronic properties; Perovskite materials; First-principles calculations; Molecular dynamics
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211379720318040

The structural, mechanical, and electronic properties of perovskite molybdates are a topic of frequent study in materials science. In this study, the influence of Mg doping on the physical metallurgy of perovskite molybdates is investigated using first-principles calculations based on density functional theory (DFT) and molecular dynamics (MD) simulation. Our calculated optimized lattice parameters (3.9945, 3.8964, 3.8634, 3.8440, and 3.7952 Å [mentioned only DFT data, MD data listed in Table 2] for x = 0, 0.1, 0.2, 0.3, and 0.4 respectively) of SrMo1−xMgxO3 are highly consistent with other experimental results (3.9762, 3.9695, and 3.9649 Å for x = 0, 0.1, and 0.2 respectively) and some available theoretical results (3.9720 Å for x = 0, no previous data available for Mg-doped systems). The calculated elastic constants satisfied the Born stability criteria, indicating that our studied materials are mechanically stable at all doping concentrations, which was also confirmed by the calculated negative values of Cohesive energy. The mechanical behaviors of perovskite, including elastic constants, elastic moduli, ductility, and elastic anisotropy, were investigated and discussed. Our computed results suggest that Mg doping can increase elastic moduli. The calculated Pugh’s ratio increased from 0.42 to 0.71 [DFT] and from 0.47 to 0.75 [MD] as well as the Poisson’s ratio decreased from 0.31 to 0.21 [DFT] and from 0.30 to 0.21 [MD] which transformed the compound from ductile to brittle due to the addition of Mg at Mo-site. The band structures, density of states, and charge density redistributions of the undoped and Mg-doped materials were predicted. Our simulation outputs clearly illustrated the importance of accounting for Mg doping’s influence in theoretical simulations of the physical properties of the presently studied perovskite material.