Optical reflectivity spectra measured on cleaved surfaces of La1-xSrxMnO3:Evidence against extremely small Drude weight

Optical reflectivity spectra were measured on cleaved surfaces of La1-xSrxM nO3 single crystals (0 less than or equal to x less than or equal to 0.30). The optical conductivity sigma(omega) shows, keeping single-component natu re, an incoherent-to-coherent crossover with a spin polarization of conduct ing epsilon(g) electrons. The sigma(omega) spectrum of the ferromagnetic-me tal La0.70Sr0.30MnO3 is characterized by a pronounced Drude-like component with large spectral A eight below similar to 1.6 eV, which yields a large e ffective carrier number N-eff* consistent with the results of other techniq ues. The present result demonstrates that the previous result of "small Dru de weight" is due to a deterioration of the sample surface, at least for th e heavily doped region.