Absorptivity of CePd3 from 5 to 400 meV

Abstract
The far infrared absorptivity of CePd3 has been measured between 4.2 and 300 K over a photon energy range which is an order of magnitude larger than previously reported. These measurements together with previous results map out the entire region of the low‐temperature CePd3 absorptivity anomaly, which is larger and extends to larger energies than extrapolation from earlier cavity measurements would suggest. The anomaly is too large to be compatible with simple conduction electron scattering off a resonant level near the Fermi energy. Above 200 meV only a weak temperature dependence is observed although a minimum in the absorptivity at 270 meV, attributed to an f multiplet transition, appears to sharpen at the lowest temperatures.