In-Plane and Out-of-Plane Optical Properties of NdBa2Cu3Ox Single Crystals close to x = 7.0

摘要

We present results of reflectivity measurements with E parallel to c and Eperpendicular to c on NdBa2Cu3Ox (Nd123) single crystals close to full oxygendoping. Along the c-axis the optical conductivity shows a well developedabsorption band around 450 cm^-1 at all temperatures. The in-plane opticalproperties are dominated by crystal-field excitations at low energies, aprominent step at 400 cm^-1 and a weaker feature between 500 - 550 cm^-1. Acomparison of the c-axis optical conductivity and the in-plane scattering ratewith neutron scattering derived spin susceptibility spectra suggests that thein-plane and out-of-plane anomalies are caused by the same mechanism, probablyelectron--spin scattering.