Complete optical spectrum ofCeAl3

We report on optical conductivity measurements performed on ${\mathrm{CeAl}}_3$ spanning the photon energy range between approximately zero and 12 eV. From the measurements at micrometer- and millimeter-wave frequencies we obtained the detailed temperature dependence of both components of the complex conductivity. These results as well as the Kramers-Kronig analysis performed on the absorptivity lead, at low temperatures, to a strongly frequency- and temperature-dependent dynamic conductivity. We analyze the optical conductivity in terms of frequency-dependent scattering rate and dynamical mass. The low-temperature effective mass is found to be ${\mathit{m}}^{\mathrm{*}}$/${\mathit{m}}_{\mathit{b}}$=325±50 in the zero-frequency limit and its temperature dependence is compared with that of the thermodynamic parameters.