Skeletal Vibrations of Cuprate Superconductor-like Phases - A Comparison of the Ft-fir Spectra of La2-xSrxCuO4, Nd2-xCexCuO4 and RBa(2)Cu(3)O(7-x) (r=ln Or Y) Powders

The FT-IR/FT-FIR spectra of powders of Nd2-xCexCuO4 and La2-xSrxCuO4 solid solutions and of RBa(2)Cu(3)O(7-x) with R = Y, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm and Yb, have been recorded at room temperature. A comparison with the published single-crystal IR data is done. An empirical assignment of the observed bands is proposed on the basis of the factor group analysis and of a discussion of the internal vibrational structure of the CuOx sheets and chains.