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Updated: Sep 11, 2025
Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties
Published on: August 15, 2015
Enhanced Oxygen Ion Conductivity and Ionic Conduction Mechanistic Visualization in Tetragonal Zircon-Type
Gaoqing Hang1, Qiulei Li1, Alberto José Fernández-Carrión2
1MOE Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China.
Abstract:
Oxide-ion conductors based on tetrahedral anion-related oxides have attracted considerable attention due to their high oxygen-ion conductivity and potential applications in clean energy devices, such as solid-state fuel cells. In this study, we report the improvement of oxide-ion conductivity by Sr2+ doping in isolated tetrahedral zircon-type PrVO4. It is found that Pr0.975Sr0.025VO4-δ features the highest oxide-ion conductivity of 2.62 × 10-3 S·cm-1 at 800 °C under air, with an oxygen transport number of 0.93. The formation and stabilization of oxygen vacancy defects, as well as the oxide-ion migration mechanism in PrVO4, were investigated through combining experimental characterizations and computing simulations. The results indicate that the concentration of oxygen vacancy defects increases with Sr2+ substitution, and the vacancies are accommodated by the formation of corner-sharing V2O7 dimers. Oxygen-ion migration proceeds via a cooperative mechanism involving V2O7-dimer breaking and reforming assisted by synergistic rotation and deformation of neighboring VO4 tetrahedra. The results provide valuable insights for further investigation and optimization of zircon-type oxides as potential oxide-ion conductors for electrochemical devices.
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