Oxygen-Isotope Effect On The High-Frequency Raman Phonons In Bi2sr2cacu2o8+Delta

Raman spectra have been obtained from single-crystal samples of Bi2Sr2CaCu2O8+delta With varying degrees of oxygen-isotope exchange. A comparison of the high-energy (greater than or equal to 400 cm(-1)) vibrational spectra obtained from an unexchanged sample, a partially exchanged sample and a fully exchanged crystal has been carried out to obtain an unambiguous assignment of the A(1g) modes at 465 and 630 cm(-1). The 465 mode is assigned to c-axis vibrations of O(3) atoms in the Bi-O layers and the 630 mode to the O(2) apical oxygen atoms in the Sr-O layers.