STRUCTURAL PERFECTION OF (001)CEO2 THIN-FILMS ON (1102) SAPPHIRE

Large-area (001) oriented epitaxial CeO2 films with extremely high cry stalline perfection characterized by x-ray diffraction rocking curves of the (002) CeO2 reflection with a full width at half maximum (FWHM) Delta omega less than or equal to 0.013 degrees acid thickness depende nt oscillations in the Bragg-Brentano x-ray diffraction spectra were d eposited via rf-magnetron sputtering on (1102) sapphire, Pole figure m easurements of the space symmetry confirmed that the examined sharp re flections belong to CeO2 and no other phases like CeAlO3 are present. The improvement of the crystalline quality was obtained by optimizatio n of the high-pressure sputter deposition process and the use of large -area substrates. The [100] CeO2 axis was slightly tilted with respect to the [1102] sapphire axis by 0.185 degrees. Subsequently sputter-de posited high-T-c YBa2Cu3O7-x thin films revealed structural properties characterized by FWHM <0.06 degrees of the (005) theta-2 theta peaks and by FWHM of the (005) peaks rocking curves of Delta omega = 0.3 deg rees. (C) 1997 American Institute of Physics.