engleski

Optical evidence for the proximity to a spin-density-wave metallic state in Na0.7CoO2

We present the optical properties of Na0.7CoO2 single crystals, measured over a broad spectral range as a function of temperature (T). The capability to cover the energy range from the far-infrared up to the ultraviolet allows us to perform reliable Kramers-Kronig transformation, in order to obtain the absorption spectrum (i.e., the complex optical conductivity). To the complex optical conductivity we apply the generalized Drude model, extracting the frequency dependence of the scattering rate (Gamma) and effective mass (m*) of the itinerant charge carriers. We find that Gamma(omega) ~ omega at low temperatures and for omega > T. This suggests that Na0.7CoO2 is at the verge of a spin-density-wave metallic phase

optical constants and parameters (condensed matter); infrared and raman spectra in inorganic crystals; visible and ultraviolet spectra of other nonmetals; effective mass and g-factors (condensed matter electronic structure)

nije evidentirano