Micro-Raman spectroscopy studies of Co doped Y-Ba-Cu-O thin films

We report on the micro-Raman spectroscopy study of thin films of YBa/sub 2/Cu/sub 3-x/Co/sub x/O/sub 7-/spl delta// grown by laser ablation. Depending on the growth pressure, the films are found to be either homogenous or inhomogeneous on a scale /spl Gt/2 /spl mu/m. In either case the films are, on average, oxygen deficient, but this deficit can be substantially improved, yielding /spl delta/ less than zero in thin film microstructures treated by oxygen electromigration. This indicates that the Co addition to such films impedes, but does not forbid the attainment of a relatively optimal degree of occupancy of the dopant, chain oxygen sites.