Elemental Substitution Effect and Physical Properties of Metallic Oxides La₅SrCu₆O15−δ

Rapid industrialization and increasing electricity demand have highlighted the urgency to reduce energy losses in power generation, accounting for over 60% of global inefficiency. Thermoelectric materials are pivotal for improving energy conversion in high-performance systems. We synthesized La5SrCu6−xFexO15−δ samples via solid-phase reaction to study elemental substitution effects on thermoelectric properties. The performance was evaluated by the dimensionless figure of merit ZT = TS2σ/κ, integrating the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ). Our results show Fe substitution significantly changes structural, electronic, magnetic, and thermoelectric properties of La5SrCu6O15−δ compound. Fe dopants improve ZT, particularly at higher temperatures, highlighting the potential application on material properties.