Atomistic Simulation of La and Mn-Doped PbBi2Nb2O9 Aurivillius Phase

Atomistic Simulation of La and Mn-Doped PbBi2Nb2O9

Abstract

This study aims to determine the effect of Mn³⁺ and La³⁺ dopants on the structure of PbBi₂Nb₂O₉ (PBN) using atomistic simulation. PBN phase geometry was optimized before the Mn³⁺ and La³⁺_-doped phase. Mn³⁺ partially substituted octahedral Nb⁵⁺ in the perovskite layer. While La³⁺partially substituted Bi³⁺ in the bismuth layer and dodecahedral Pb²+in the perovskite layer. The concentration (x) of dopants that doped PBN was made in such a way that it produces a phase of Pb_1-2xBi_{1.5 + 2x}La_0.5Nb_2-xMn_xO₉ (x = 0, 0.1, and 0.3) which was not charged. The simulation results showed that the optimized PBN cell parameters were in a good agreement with the experimental result. Increasing the concentration of dopants result in the Pb_1-2xBi_{1.5+ 2x}La_0.5Nb_2-xMn_xO₉ phase (PBNM-Bi and PBNM-A) being less stable, as indicated by the increased lattice energy. PBNLM-Bi structures experiences an elongation which was showed by the cell parameters of c increase while a and b decrease. La³⁺prefers to occupy bismuth oxide layer rather than the dodecahedral A-site of the perovskite layer. The results of this simulation can explain the PBLNM structure of experimental results that do not pay attention to the multiplicity of doped PBN with certain dopant concentrations.