Non-Fermi-Liquid Behavior of SrRuO{sub 3} : Evidence from Infrared Conductivity

The reflectivity of the itinerant ferromagnet SrRuO{sub 3} has been measured between 50 and 25thinsp000thinspthinspcm{sup {minus}1} at temperatures ranging from 40 to 300thinspthinspK, and used to obtain conductivity, scattering rate, and effective mass as a function of frequency and temperature. We find that at low temperatures the conductivity falls unusually slowly as a function of frequency (proportional to 1/{omega}{sup 1/2} ), and at high temperatures it even appears to increase as a function of frequency in the far-infrared limit. The data suggest that the charge dynamics of SrRuO{sub 3} are substantially different from those of Fermi-liquid metals. {copyright} {ital 1998} {ital The American Physical Society }