Exploring the impact of multivalent substitution on high-temperature electrical conductivity in doped lanthanum chromite perovskites: An experimental and ab-initio study

Doped LaCrO₃ perovskites hold promise as robust materials for electrical interconnects and sensor applications in harsh environments. In this work, we investigated the high-temperature behavior of La_1–xSr_xCrO₃, La_1–xCa_xCrO₃ and La_0.8Sr_0.2Cr_1-x Mn_xO3 (0.1 ≤ x ≤ 0.4) through a combination of computational modeling and physical characterization up to 1500 °C. Crystalline structural properties were determined and compared with ab-initio calculations, which demonstrated excellent agreement with experimental findings. High-temperature electrical conductivity measurements were performed under different atmospheres. Calcium and strontium/manganese co-doped lanthanum chromites exhibited typical semiconductor exponential trends and conductivity showed proportional correlation with substitutions levels up to 30 %. The DFT modelling was completed up to 1500 °C, including low and high temperature chromite phases and oxygen vacancies insertion. Calculations were correlated with experimental electrical properties. This work expands the understanding of doped lanthanum chromites and paves the way for the development of materials suitable for demanding high-temperature applications.. Authors: Mena, Javier A. [West Virginia University, Morgantown, WV (United States); West Virginia University Research Corporation]; Mendoza-Estrada, Víctor [Universidad del Norte, Barranquilla (Colombia)]; Sabolsky, Edward M. [West Virginia University, Morgantown, WV (United States)]; Sierros, Konstantinos A. [West Virginia University, Morgantown, WV (United States)]; Sabolsky, Katarzyna [West Virginia University, Morgantown, WV (United States)]. DOE Contract: FE0031825. Subjects: 20 FOSSIL-FUELED POWER PLANTS; Ab-initio calculations; High-temperature conductivity; Materials in extreme conditions; Perovskite LaCrO3; Solubility limit