Kuru Y, Marrocchelli D, Bishop S R, et al. Anomalous chemical expansion behavior of Pr0. 2Ce0. 8O2-δ thin films grown by pulsed laser deposition[J]. Journal of the Electrochemical Society, 2012, 159(11): F799.

ABSTRACT

The chemomechanical and electrical properties of (Pr,Ce)O2-δthin films were studied between 30 and 875◦C in air by in situ X-raydiffraction and complex impedance spectroscopy measurements. Reduction/oxidation reactions produced large stress variations(∼2 GPa) in the structure. Atomistic simulation techniques were employed to investigate the mechanisms behind the observedchemical expansion behavior, suggesting the possible roles of defect ordering upon cooling and heating. An alternative explanationbased on a metastable frozen in state of higher reduction is also considered. Similar phenonena, observed here in Pr0.2Ce0.8O2-δ,are expected to be applicable and of potential significance for other technologically important complex oxides such as perovskite-structured materials