Optical spectra measured on cleaved surfaces of double-exchange ferromagnet La1-xSrxMnO3
K. Takenaka, K. Iida, Y. Sawaki, S. Sugai, Y. Moritomo, A. Nakamura
Abstract
Optical reflectivity spectra were measured on cleaved surfaces of La1-xSrxMnO3 single crystals (x=0.175, T_C=283 K) over a temperature range 10-295 K. The optical conductivity
sigma(ω)
shows, keeping single-component nature, incoherent-to-coherent crossover with increase of electrical conductivity. The
σ(ω)
spectrum of low-temperature ferromagnetic-metallic phase (10 K) exhibits a pronounced Drude-like component with large spectral weight, contrary to the previous result. The present result indicates that the optical spectrum of the manganites is sensitive to condition of sample surfaces.