The influence of the technological parameters on the ionic conductivity of samarium doped ceria thin films

Abstract

Sm0,20Ce0,80O2 powder was used for the formation of samarium doped cerium oxide (SDC) thin films using e-beam physical vapour deposition. Surface area of powder was 34.9 m2/g and particle size – 0.3 μm – 0.5 μm. Thin films were deposited using physical vapor deposition system on SiO2 (optical quartz) and Alloy 600 substrates. The deposition rate 0.2 nm/s ÷ 1.6 nm/s and substrate temperature 20 °C ÷ 600 °C were used. Ionic conductivity investigation revealed that the maximum ionic conductivity (1.67 S/m) has the thin film deposited on 300 °C temperature substrate using 0.4 nm/s deposition rate. Minimum ionic conductivity (0.26 S/m) has thin film, which was deposited on 20 °C temperature substrate using 0.8 nm/s deposition rate. Vacancy activation energies vary in 0.87 eV÷ 0.97 eV range. Furthermore the calculations of crystallite size revealed that crystallite size increases with increasing substrate temperature: from 7.50 nm to 46.23 nm on SiO2 substrate and from 9.30 nm to 44.62 nm on Alloy 600 substrate. Molar concentration of samarium in initial evaporated material is 19.38 mol % and varies from 11.37 mol % to 21 mol % in formed thin films depending on technological parameters.