Abstract:
In this study, Calcium Doped Ceria (CDC) thin film is prepared by the two steps, in the first
step calcium doped ceria (CDC) powder is synthesized by co-precipitation method and in the
second step, the slurry of calcium doped ceria (CDC) with ball milling and then thin film is
casting with help of Tape casting technique. The fabricated thin films were sintered in the
range of temperatures (150-750) ℃, in an air atmosphere. Crystal structure revealed that thin
film has a cubic fluorite structure, and its average crystallite size is in the range of (53-42)
nm. Raman analysis of the thin film was done in the temperature range of 350-750℃. These
results showed that CDC thin films have high oxygen vacancies as sintering temperature rises.
Which was depicting the high conductivity of the thin film. These results were also verified
by the Conductivity measurements. The increase in FWHM of main peaks of Raman spectra,
with an increase in temperature resulting in reduction of the crystallite size. Which was also
confirmed by XRD results. FTIR results showed the formation of the Ce-O bonds, OH
stretching, etc. Furthermore, FTIR spectra of the thin film at various temperatures indicated
that OH stretching decreased as temperature increased, indicating that moisture in the sample
reduced. Uv visible analysis was done at two different temperatures, 150 and 750℃. Band
gap values decreased with increase in the temperatures. It was 3.22eV at 750oC and 3.3eV at
150℃. The conductivity measurements showed that conductivity of thin film was increasing
as sintering temperature rises. which was confirmation of Raman results. Thin-film showed
the highest conductivity 0.052 Scm-1
at 750℃, the activation energy and electrical band gap
calculated from the Arrhenius plot are 0.25 eV and 0.5 eV for the sample sintered at 750oC,
respectively. EIS spectra thin-film sintered at 750℃ and 150℃ showed semicircle, which
confirms the ionic behavior of the CDC electrolyte thin film. The ohmic resistance also
decreased with an increase in the sintering temperature. These results revealed that the thin
film shows high ionic conductivity at intermediate temperatures. Which makes it useful for
SOFC application
