Title :
Resonant Rutherford backscattering studies of cerium oxide thin films deposited by RF sputtering
Author :
Chin, C.C. ; Lin, R.J. ; Yu, Y.C. ; Wang, C.W. ; Lin, E.K. ; Tsai, W.C. ; Tseng, T.Y.
Author_Institution :
Inst. of Astron. & Astrophys., Acad. Sinica, Taiwan
fDate :
6/1/1997 12:00:00 AM
Abstract :
We have studied the stoichiometry of cerium oxide films deposited by RF sputtering on sapphire and MgO as a function of deposition conditions using the resonant Rutherford backscattering method. We found that some films have the off-stoichiometry of CeO/sub y/ with y greater than 2.0. Such an off-stoichiometry cannot be due to a mixture of the known phases of bulk cerium oxide samples. This may be due to either cerium vacancies or interstitial oxygen atomic impurities. The cerium ion X-ray photoemission spectra of those films cannot determine the vacancy of the cerium ions. The c-axis YBaCuO thin films deposited by sputtering on the CeO/sub 3.3/ buffer layer on sapphire was found to be epitaxial. The T/sub c/ was 86 K with /spl Delta/ T/sub c/ less than 1 K.
Keywords :
Rutherford backscattering; X-ray photoelectron spectra; barium compounds; high-temperature superconductors; interstitials; sputter deposition; stoichiometry; superconducting epitaxial layers; vacancies (crystal); yttrium compounds; 86 K; Al/sub 2/O/sub 3/; CeO-Al/sub 2/O/sub 3/; CeO/sub 3.3/ buffer layer; CeO/sub x/ thin films; RF sputtering; X-ray photoemission spectra; YBaCuO; YBaCuO thin films; critical temperature; interstitials; off-stoichiometry; sapphire substrate; stoichiometry; vacancies; Atomic layer deposition; Backscatter; Buffer layers; Cerium; Impurities; Photoelectricity; Radio frequency; Resonance; Sputtering; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
