RAMAN STUDIES ON Y1-xNdxBa2Cu3O7-delta HIGH T-c SUPERCONDUCTORS

Abstract

We have studied in detail the temperature dependence of the Raman bands corresponding to the CuO2 planar vibrations in Y1-xNdxBa2Cu3O7-delta. For x < 0.4, the similar to 340 cm(-1) phonon has main interaction with superconducting electrons and the observed phonon anomaly at low temperature can be well explained by the Zeyher-Zwicknagle theory, but for x > 0.6 the main interaction of the phonon seems to be with (Nd3+) 4f electrons and an additional mechanism based on the interaction with the crystal field excitation seems to contribute to the double peak splitting anomaly of the phonon at low temperature.