Strain evolution and morphological transition of magnetron-sputtered CeO2 thin films induced by deposition parameters

• CeO2 film strain evolutions were induced by deposition parameters.
• Deposition parameters also led to distinct CeO2 morphological transition.
• Strain evolution mechanism was discussed based on “atomic peening” theory.
• Correlation between film strain and morphology was established.
• CeO2 films with desired morphology can be controllably fabricated.

Cerium dioxide (CeO2) films were fabricated on yttria-stabilized zirconia (YSZ) single crystals using unbalanced radio frequency (RF) magnetron sputtering. X-ray diffraction measurements revealed film strain discrepancies under different deposition parameters. Strain evolution was induced by varying sputtering pressure, RF power, and sputtering gas. A distinct morphological transition from a granular surface to an interwoven surface was also realized by varying the above parameters. On the basis of the “atomic peening” mechanism, the influence of different parameters on film strain was discussed. The film surface characteristics were revealed to be highly correlated with film strain. YBa2Cu3O7−δ (YBCO) films were post-deposited on the as-grown CeO2/YSZ(001) stack by using the trifluoroacetate metal-organic deposition (TFA-MOD) method. The superconducting property of the YBCO layer varied significantly with the morphology of the CeO2 buffer films.