Raman Study Of The Hg0.7cr0.3sr2cuo4+Delta Superconductors

The focal environment of the apical oxygens (O-A) in the Sr-substituted mercury-based superconductor Hg0.7Cr0.3Sr2CuO4+delta is investigated using Raman spectroscopy. Raman spectra from the Sr-substituted Hg-1201 samples show broad O-A A(1g) double peaks at 553 and 583 cm(-1), which are 10 - 20 cm(-1) lower than the pristine Hg-1201. The existence of, and lower shift of, the double peaks in the Raman spectra of the Sr-substituted Hg-1201 superconductors indicate changes in the environment of O-A in the Sr-substituted mercury-based superconductors.