Raman Scattering Studies of ${\rm YBa}_{2}{\rm Cu}_{3}{\rm O}_{7-{\rm x}}$ Films Grown by High-Rate e-Beam Co-Evaporation

We present results of Raman scattering studies of superconducting YBa
₂
Cu
₃
O
_7-x
(YBCO) films grown by a high-rate electron-beam co-evaporation method. It is shown by X-ray diffraction that the as-grown YBCO films have a highly c-axis oriented and in-plane aligned texture. Raman scattering measurements were used to study optical phonon modes, oxygen content and second phases of the YBCO coated conductors. Raman spectra of YBCO films with lower-transport properties exhibit additional phonon modes at ~ 300 cm
^-1
, ~ 600 cm
^-1
, and ~ 630 cm
^-1
, which are related to second-phases such as Ba
₂
Cu
₃
O
_5.9
and BaCuO
₂
. We also performed micro-Raman scattering measurements, which enable the local characterization of the material over a few micrometer scales. We could clearly determine the chemical homogeneities of the films on which we could not have information using XRD. Our results strongly suggest that micro-Raman scattering can be a very effective tool for characterizing structural and chemical properties, which is essential for optimizing growth conditions.