Future Research Direction on Rare-Earth and Alkaline-Earth Metal-Doped LaMnO3 Perovskites

Lanthanum manganite (LaMnO₃) and its doped derivatives have become an important class of perovskite materials due to their adaptable structural, electronic, and magnetic properties. A-site substitution with rare-earth elements and alkaline-earth elements has been shown to manipulate the Mn³⁺/Mn⁴⁺ ratio, alter oxygen vacancy concentrations, and perturb lattice distortions; all of this can impact conductivity, catalytic activity, and magnetism. These properties render a wide variety of applications appealing for doped LaMnO₃ materials, including solid oxide fuel cells, catalysis, spintronics, and energy storage. Even so, several challenges have limited their broader use, such as secondary-phase formation, electrolyte reactivity, dopant segregation, and processing at high temperatures. This article discusses advancements toward addressing these challenges with synthesis, defect engineering, and computational methods. Additionally, it reflects on the potential of new tools (machine learning and nanoscale design) to speed up the discovery of optimized compositions and processing conditions. Despite present problems, doped LaMnO₃ perovskites remain a promising material for energy and electrical applications.