Evaluation of the Oxygen Migration Energy in Doped Ceria by Terahertz Spectroscopy

We measure the terahertz conductivity of doped ceria by terahertz time-domain spectroscopy at different temperatures to characterize the shape of the potential associated with microscopic ion hopping. The experimental results for Gd-and La-doped ceria show that the activation energy in doped ceria is larger than that in stabilized zirconia. This result can be explained by a simple rigid-body model with the assumption of doping-induced lattice expansion, i.e., by considering the gap between cations. Our results for conventional fluorite-type solid-oxide electrolytes show that terahertz spectroscopy can be used to investigate fast microscopic ionic conduction in various electrolytes, which cannot be accessed through conventional impedance measurements.

Automated summary

Terahertz conductivity of doped ceria was measured at different temperatures, showing higher activation energy in doped ceria compared to stabilized zirconia, possibly due to lattice expansion. Terahertz spectroscopy can also be used to study fast microscopic ionic conduction in solid-oxide electrolytes, inaccessible through conventional impedance measurements.