EX-SITU FLUORINATION OF OXYGEN-DEFICIENT YBA2CU3OX THIN-FILMS DEPOSITED BY LASER-ABLATION ON (100)SRTIO3 SUBSTRATES

Oxygen deficient YBa2Cu3Ox thin films, in-situ deposited by laser abla tion on (100)SrTiO3 substrates have been treated ex-situ under diluted NF3 flow at 280 degrees C. After a short time of treatment, a clear i mprovement of the superconducting behaviour, i.e. an increase of Tc an d a decrease of the inductive transition width are observed. Compariso ns are made between reactions under NF3 and under O-2 or N-2 in the sa me conditions of reactions, leading to the conclusion that in all case s the NF3 treatment is the best to improve the superconducting behavio ur of these thin films. The kinetics of the NF3 reaction with these fi lms is compared to the one previously observed for oxygen deficient th in films deposited by laser ablation on (100)MgO.