The grain and grain boundary impedance of sol–gel prepared thin layers of yttria stabilized zirconia (YSZ)

Abstract

Separating grain and grain boundary impedance contributions of ion conducting thin films is a highly non-trivial task. Recently, it could be shown that long, thin, closely spaced, and interdigitally arranged electrodes enabled such a separation on pulsed laser deposited yttria stabilized zirconia (YSZ) thin films. In this contribution, the same approach was used to investigate YSZ layers prepared by the sol-gel route on sapphire substrates. Grain and grain boundary properties were quantified for layers between 28 and 168 nm thickness. Only for the thinnest of the investigated layers, a deviation from macroscopic bulk properties was found, which could be correlated to interfacial strain in the epitaxial layer. A dependence of the preferential orientation on the film thickness was found.