We present results of Raman scattering studies of superconducting YBa 2Cu3o7-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 Ba2Cu3O 5.9 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.
Bibliographical noteFunding Information:
Manuscript received August 29, 2006. This work was supported in part by a Grant (R-2004-0-194) from Ministry of Commerce, Industry and Energy (MOCIE), Republic of Korea, and in part by a Grant from Center for Applied Superconductivity Technology of the 21st Century Frontier R&D Program funded by the Ministry of Science and Technology, Republic of Korea. E. Lee is with the Division of Nanosciences, Ewha Womans University, Seoul, 120-750, Korea. H. R. Yoon is with the Department of Physics, Ewha Womans University, Seoul, 120-750, Korea. W. Jo and S. Yoon are with the Department of Physics and Division of Nanosciences, Ewha Womans University, Seoul, 120-750, Korea (e-mail: email@example.com; firstname.lastname@example.org). H. Cheong is with the Department of Physics, Sogang University, Seoul 121-741, Korea. H. G. Lee and G. W. Hong are with the Graduate School of Energy, Korea Polytechnic University, Gyeonggi-Do 429-793, Korea. J. U. Huh, R. H. Hammond, and M. R. Beasley are with the Geballe Lab for Advanced Materials, Stanford University, Stanford, CA 94305 USA. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2007.899434
- Local chemical variation
- Raman scattering
- YBCO films