Microstructural Effects in Textured Neodymium Doped Ceria

Neodymium doped ceria (NDC) is a promising candidate for use as an electrolyte in a solid oxide fuel cell (SOFC) due to its high ionic conductivity, low electronic conductivity, and good sinterability and stability.  It is well known that grain size and grain boundary effects can significantly impact the observed ionic conductivity of ceria in the bulk and particularly in thin films.  This work focuses on the influence grain size (film thickness) and grain boundary configuration have on the ionic conductivity of NDC.  To this end, textured NDC thin films of varying thicknesses and grain sizes were grown on sapphire substrates using pulsed laser deposition (PLD).  We will present broadband impedance data analysis on across plane and in-plane electrode configurations collected as a function of temperature.  The separate effects of film thickness, grain size, and grain boundary on the observed ionic conductivity will be discussed based on the contrasting data from the two measurement configurations.