We have investigated the phonon Raman spectra of YBa2Cu3-xCoxO7-δ ceramic samples prepared by both solid state reaction and a polymerized complex method using Raman microprobe collection optics. With increasing Co content the frequencies of the Ba, Cu(2), O(2)-O(3) and the apical oxygen O(4) c-axis vibrational modes change considerably. The changes are compared with changes of interatomic bond distances as obtained by neutron diffraction and indicate charge transfer effects between the CuO2 planes and the CuO chains with increasing Co substitution. The CuO2 plane oxygen mode at 336 cm-1 exhibits slightly decreased coupling to the electronic states with increasing Co content.
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