Investigations on the Structural and Electronic Properties of Pure and Doped Bulk Pr_2NiO_4 through First Principles Calculations

摘要

Pr_2NiO_4-based ceramic oxides are known promising MIEC cathodes material for SOFC, owing to its experimentally found good ionic and electronic conductivity compared with other known materials. In this study, the structural and electronic properties of pure and doped Pr_2NiO_4-based oxides are investigated through first principles calculations based on density functional theory (DFT) in an attempt to investigate the possibility of using this material as an SOFC electrolyte. Substitutional doping at the cation site [Pr_(2-y)R_yNi_(1-x-y-z)E_xT_zO_4 (R=La, and E=Cu and T=Ga)] shows change in both structural and electronic properties. Higher concentration of La doping increases the lattice parameter along the c direction while maintaining the electronic property of the host system. On the other hand, Cu doping causes tilting of the nickelate octahedral substructures so as to stabilize the whole structure but accompanies emergence of states which can contribute to electronic conduction. However, Ga doping has indications of high O ion diffusion and lower electronic conductivity.