STRUCTURAL INVESTIGATIONS OF POLYCRISTALLINE YBCO THIN FILMS AND CERAMICS BY X-RAY AND STEM

posited up to a thickness of Ipm on a non intentionally heated substrate (below 10°C). The films were amorphous and so needed a post-thermal treatment under an ambient. Surface crystallization has been studied under ultra-high vacuum in a 100 KeV scanning transmission electron microscope ( STEM VG HBSOIA ). Ex-situ annealing has been made in a classical furnace at atmospheric pressure with controlled gas composition, the rise of temperature was canied out under He gas with or without O2 while the cooling was performed under pure 02.Their lattice parameters and preferred orientation were measured with a Seifert MZ-IV