Direct estimations of the low-energy (0.5-6meV) complex optical spectrum in
La0.7Ca0.3MnO3 thin films have been investigated using terahertz time-doma
in spectroscopy. At low temperature. a clear Drude-term appears. Using the
simple Drude model. we have estimated the scattering rate and the plasma fr
equency in the ferromagnetic metallic ground-state. Low-energy charge dynam
ics are briefly discussed on the basis of present results. (C) 2001 Publish
ed by Elsevier Science B.V.