Fluorination Under NF$\text{}_{3}$ Flow of Oxygen Deficient YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{x}$ Thin Films Deposited on Various Types of Substrate

Oxygen deficient YBaCuO thin films, c-epitaxially grown by laser ablation on different substrates such as (100)MgO, (100)SrTiO$\text{}_{3}$ and (100)LaAlO$\text{}_{3}$, were fluorinated by an ex situ solid/gas reaction with NF$\text{}_{3}$ (3% NF$\text{}_{3}$ diluted in N$\text{}_{2}$) at 280°C. The kinetics of the reaction depends on the type of the substrate. After reaction the superconducting behaviour of the films is improved without degradation of their crystallinity, whatever the nature of the substrate. The stability of the fluorinated films under oxygen or nitrogen gas was studied. All these results will be compared with those previously obtained for fluorination of oxygen deficient YBaCuO ceramics.