Raman scattering studies of YBa2Cu3O7-x films grown by high-rate e-beam co-evaporation

초록

We present results of Raman scattering studies of superconducting YBa2Cu3O7-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 similar to 300 cm(-1), similar to 600 cm(-1), and similar to 630 cm(-1), which are related to second-phases such as Ba2Cu3O5.9 and BaCuO2. 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.

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