Ex-situ fluorination of oxygen deficient YBa2Cu3Ox thin films deposited by laser ablation on (100) SrTiO3 substrates

Oxygen deficient YBa 2 Cu 3 O x thin films, in-situ deposited by laser ablation on (100) SrTiO 3 substrates have been treated ex-situ under diluted NF 3 flow at 280°C. After a short time of treatment, a clear improvement of the superconducting behaviour, i.e. an increase of Tc and a decrease of the inductive transition width are observed. Comparisons are made between reactions under NF 3 and under O 2 or N 2 in the same conditions of reactions, leading to the conclusion that in all cases the NF 3 treatment is the best to improve the superconducting behaviour of these thin films. The kinetics of the NF 3 reaction with these films is compared to the one previously observed for oxygen deficient thin films deposited by laser ablation on (100) MgO.