|About this Abstract
|Materials Science & Technology 2020
|High Entropy Materials: Concentrated Solid Solution, Intermetallics, Ceramics, Functional Materials and Beyond
|Chemical Defect Reactivity of A-site High-Entropy LaFeO3 and LaMnO3 Based Perovskite Oxides
|Hector Alexis De Santiago, Wei Li, Wenyuan Li, Xingbo Liu
|On-Site Speaker (Planned)
|Hector Alexis De Santiago
Perovskite oxides have demonstrated fascinating properties. Herein, high-entropy perovskite oxides (HEPOs) of LaMnO3 and LaFeO3 were synthesized, in equimolar A-site composition with tunable rare metal elements of Pr3+, Gd3+, Nd3+, Ba2+ and Sr2+, through a modified Pechini sol-gel method. The effects of high-entropy A-site elements on the kinetic properties of these mixed ionic and electronic conductors were systematically investigated. The XRD corroborated the stabilization of single phase for the synthesized HEPOs which retain stability after being exposed to high temperatures. Furthermore, the electrical conductivity relaxation studies demonstrated that HEPOs changes to new thermodynamic stability isothermally under atmospheric oxygen partial pressure (pO2), indicating Schottky defect reaction controlled p-type conductivity. Furthermore, the conductivity relaxation time for thermodynamic stability at atmospheric and low pO2 require long time, due to the formation of Schottky defects or the stabilization of the high configurational entropy. Further work will focus on exploring the B-site high entropy stabilization.