Microcontact impedance spectroscopy in nitrogen-graded zirconia

Impedance spectroscopy with spatial resolution using a microcontact array has successfully been applied to nitrogen-graded zirconia to establish the conductivity variation with nitrogen dopant concentration. Impedance profiles were measured in two configurations: 1) using one microelectrode versus a large counter electrode and 2) measuring between two microelectrodes. A versatile equivalent circuit model was introduced which allows a straightforward analysis of the obtained spectra which exhibit inductive loops as frequently associated with two-microcontact measurements. The analysis unambiguously revealed a local conductivity anisotropy in the material.