Structural Characterization and Electrical Conductivity of Mechanically Alloyed 10mol% In2O3–Doped CeO2 Nanoparticles

Method: Nanocrystalline powder of 10 mol% indium oxide doped ceria is synthesized by mechanically alloying the stiochiometric powder mixture of CeO2 and In2O3 within 5 h of milling in open air. Further milling up to 8 h confirms the stable cubic structure of the compound with increase in milling time. Objective: Detailed structure and microstructure of the compound have been characterized by Rietveld powder structure and microstructure refinement method using XRD data and analyzing HRTEM images. Effect of In2O3 doping on electrical conductivity of nanocrystalline CeO2 is studied by measuring the electrical conductivity of the compound in the temperature range 300°C-600°C. The DC conductivity of doped ceria (σdc ~ 3x10-4 S/cm at 540°C for doped ceria) has been enhanced to ~100 times in comparison to that of the undoped ceria (σdc~ 4x10-6 S/cm at 540°C) nanoparticles has been found. Conclusion: This significant increment in electrical conductivity has been interpreted through the microstructure characterization of the doped compound.