Microstructure and electrical properties of barium cerate thin films

Single-phase barium cerate films of 1.5 µm thickness were deposited using an e-beam physical vapor deposition method and studied using X-ray diffractometry, scanning electron microscopy, and impedance spectroscopy. The films deposited on the Inconel 600, MgO, YSZ, and Al 2 O 3 substrates at 500–700 °C differed in morphology, grain sizes, crystallographic orientation, and electrical properties. The mechanism of film growth was found to depend on the substrate and deposition temperature. The films on metallic substrates require a lower temperature to form a single-phase barium cerate phase. The values and activation energy of conductivity were found to depend mainly on the film microstructure, in particular on the crystallographic orientation of grains. The relaxation of strained films causes a decrease in conductivity.