Transference Numbers for In-Plane Carrier Conduction in Thin Film Nanostructured Gadolinia-Doped Ceria Under Varying Oxygen Partial Pressure

摘要

We demonstrate a modified Hebb-Wagner approach to quantitatively estimate transference numbers for carrier conduction in thin film oxide conductors using blocking electrodes in an in-plane geometry. We report ionic transference numbers, t_i, for gadolinia-doped ceria (GDC) thin films, a model mixed ion-electron conductor, at 973K and oxygen partial pressure ranging from 0.21 atm down to approximately 10~(22) atm. Our results indicate that GDC reaches the electrolytic regime (t_i = 0.5) at an oxygen partial pressure of 5 × 10~(-19) atm at 973K. This approach may be useful for understanding carrier transport mechanisms in low-dimensional oxide heterostructures with specific relevance to nanostructured energy materials.