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Title: The mechanism of sputter-induced epitaxy modification in YBCO (001) films grown on MgO (001) substrates

Journal Article · · Journal of Materials Research
; ; ; ;  [1]; ; ; ; ; ;  [2]
  1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  2. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60201 (United States)

The sputter-induced epitaxy change of in-plane orientation occurring in YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} (001) thin films grown on MgO (001) substrates by pulsed organo-metallic beam epitaxy (POMBE) is investigated by a series of film growth and characterization experiments, including RBS and TEM. The factors influencing the orientation change are systematically studied. The experimental results suggest that the substrate surface morphology change caused by the ion sputtering and the Ar ion implantation in the substrate surface layer are not the major factors that affect the orientation change. Instead, the implantation of W ions, which come from the hot filament of the ion gun, and the initial Ba deposition layer in the YBCO film growth play the most important roles in controlling the epitaxy orientation change. Microstructure studies show that a Ba{sub x}Mg{sub 1{minus}x}O buffer layer is formed on top of the sputtered substrate surface due to Ba diffusion into the W implanted layer. It is believed that the formation of this buffer layer relieves the large lattice mismatch and changes the YBCO film from the 45{degree} oriented growth to the 0{degree} oriented growth. {copyright} {ital 1998 Materials Research Society.}

DOE Contract Number:
W-31-109-ENG-38
OSTI ID:
289220
Journal Information:
Journal of Materials Research, Vol. 13, Issue 12; Other Information: PBD: Dec 1998
Country of Publication:
United States
Language:
English