Frequency and temperature dependence of conductivity for perovskite titanates

Frequency- and temperature-dependent conductivity has been studied by optic al spectroscopy for perovskite titanates, which are typical three-dimension al correlated metals. Extended Drude analysis of the data indicates that on ly one parameter, the T-2 coefficient of the-scattering rate, dominates the temperature dependence of conductivity over a wide energy range (from dc t o similar to 1 eV); This result is consistent with the Fermi-liquid theory in the low-frequency limit, and can be regarded as a prototypical behavior of correlated metals. [S0163-1829(99)12235-5].