Raman spectrum of Ba-Y-Cu-O system

The Raman spectra of a set of samples with nominal composition Ba x Y 1−x CuO 3 (0.005 ⩽ x ⩽ 0.8) which are synthesized under the same condition have been measured. It is observed that the main characters of Raman spectrum are quite different for the two groups of samples with Ba concentration being 0.3 ⩽ x ⩽ 0.8 and 0.005 ⩽ x ⩽ 0.075 respectively. It just coincides with the results two types of phase structures and the difference in superconductivity related to the two ranges of composition. Based on a comprehensive analysis of the results above, the authors suggest that the Raman peak near 605cm -1 likely corresponds to the vibration of CuO 6 octahedra breathing-mode, which play an important role in this system for achieving high transition temperature.