We present results of Raman and infrared spectroscopic studies of the composite system of superconducting YBa2Cu3O7-δ and metallic BaPbO3, with the BaPbO3 fraction ranging from 5 to 30 in weight. The Raman spectra of the YBa2Cu3O7-δ grains in the composite system are typical of well-oxygenated YBa2Cu3O7-δ bulk single crystals, even up to the grain boundaries, independent of the BaPbO3 fraction. We have also performed infrared reflectivity measurements and have identified the major c-axis transverse-optical phonons of YBa2Cu3O7-δ, consistent with the single-crystal data, confirming that the constituent YBa2Cu3O7-δ crystallites are fully oxygenated. The absence of mode splitting suggests that the crystal symmetry of YBa2Cu3O7-δ grains remains the same as that of bulk single crystals. No phonons indicative of other YBa2Cu3O7- or BaPbO3-related impurity phases, such as YBa2Cu3O6, Y2BaCuO5, and Ba2PbO4, have been detected in our Raman and infrared spectra. All these optical features clearly indicate that YBa2Cu3O7-δ is well separated from BaPbO3 and that BaPbO3 is an excellent additive material for the synthesis of YBa2Cu3O7-δ bulk materials.
|Number of pages||7|
|Journal||Physica C: Superconductivity and its Applications|
|State||Published - 1 Nov 1998|
- Infrared spectroscopy
- Intergranular material
- Raman spectroscopy