On the Synthesis of PdO−RuO2 Solid-Solution Thin Films by Thermal Oxidation and Investigation of Their Gas-Sensing Properties

Abstract

The phase and structural transformations that Pd–Ru(7 at %) solid solution thin films undergo during thermal oxidation in oxygen in the temperature range 570–1070 K are studied by transmission electron microscopy, high-energy electron diffraction, and reflection high-energy electron diffraction. With increasing oxidation temperature, the phase composition is found to change in the order: Pd–Ru(7 at %) solid solution → Pd–Ru(7 at %) + PdO + RuO₂ → PdO + RuO₂ → PdO–RuO₂ solid solution. We show that the complete oxidation of Pd–Ru(7 at.%) thin films to form single-phase films of the PdO–RuO₂ solid solution takes place at a temperature of 100 K higher compared to pure palladium films. The resistance sensor response of the prepared PdO−RuO₂ oxide films to ozone in air is studied for the first time. The results suggest that this is a promising material for use in gas-sensing applications.