Solid oxide fuel cells (SOFC) Thin films Thermal treatment
Samarium doped cerium oxide (SDC) thin films were grown evaporating cubic phase cerium oxide doped by 15% of samarium nanopowder (Sm 0.15 Ce 0.85 O 1.95 ). SDC thin films were formed on Alloy 600 (Fe-Ni-Cr) and optical quartz (SiO 2 ) substrates using e-beam deposition technique controlling (influencing thin film properties) deposition parameters: substrate temperature and electron gun power. SDC thin films (1.5-2 ฮผm of thickness) were deposited when the electron gun power was 0.12 kW, 0.3 kW, 0.45 kW, 0.6 kW, and 0.78 kW during thin films deposition. The formed SDC thin films were studied by scanning electron microscopy (SEM), Energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). It was determined that electron gun power (in the range from 0.12 kW to 0.78 kW) has the influence on crystallite size (increased from 5 nm to 19.2 nm) which increases as the gun power increases. The crystallite size increases from 12 nm to 47 nm by increasing substrate temperature from 100 ยฐC to 600 ยฐC. The texture of formed SDC thin films is not influenced by e-beam gun power, but it is influenced by substrate temperature when it is above 300 ยฐC. Deposited SDC thin films are stoichiometric and repeat the stoichiometry of elements of the chosen evaporated SDC material. The deposited SDC films were annealed in air to 800 ยฐC temperature and were investigated by X-ray diffraction (XRD) in order to understand the stability and influence the temperature on the structure of formed thin films. The thermal treatment shows that deposited SDC thin films are stable and the crystallite size and texture are not changing during the heating and cooling.