INTERCALATION OF BI2SR2CACU2O8-CRYSTAL WITH C-60 - CHARACTERIZATION AND MICRO-RAMAN INVESTIGATION(DELTA SINGLE)

Micro-Raman and corroborative photoluminescence (PL); infrared (IR) ab sorption; scanning tunneling microscopy/spectroscopy (STM/STS) and x-r ay diffraction (XRD) studies on the intercalation of Bi2Sr2CaCu2O8+del ta (Bi-2212, host) with C-60 (guest) reveal that intercalation drastic ally changes vibrational, electronic, and structural characteristics o f both the guest and the host species. The predominant changes in vibr ational modes such as splitting (651, 668 cm(-1)) in the radial mode ( at 709 cm(-1)); anomalous intensity distribution; and appearance of fo rbidden modes in the Raman spectra of the guest have been related to t he symmetry reduction in the guest sublattice and to the induced reson ance effects due to the intercalation process. Further, the changes in Raman spectra corresponding to the host, such as the appearance of a strong Raman mode at 310 cm(-1) (in the v(Cu-O) region), redshift in t he v(Bi-O) mode, and the appearance of a band at 1443 cm(-1) in the ta ngential mode region of the guest reveal the formation of semiconducti ng islands in the host sublattice due to the guest-host electron trans fer process. Raman results have been correlated with PL, IR, STM/STS, and XRD data. (C) 1997 American Institute of Physics.