Thermal Evolution and Stability of Pr2O3-doped ZrO2 Powder and Thin Films

Abstract ZrO2 powders and films with 5, 8, 9 and 10 mol % of Pr2O3 were prepared by a modified sol-gel method using liquid precursors. The thermal stability of the different phases is crucial in order to use this material in devices such as fuel cells, where the appearance of unwanted spurious phases causes a negative impact in the efficiency of such devices. DTA-TG and HT-XRD analysis carried out on the powders show that crystallization takes place around 500 °C. Heat treatments over 1000 °C produces destabilization of the initial crystallization cubic phase in the powders as well as in the films. However, aging treatments consisting in thermal cycles between room temperature and 750 °C, which is the temperature of technological interest, do not affect the structure, the microstructure and the stresses state of the Pr-doped ZO2 thin films.