Infrared diffuse reflectivity study of high-Tcsuperconductors

Abstract

We have measured the spectral dependence of the diffuse reflectivity of polished sintered pellets of YBa2Cu307y La2 -Sr"Cu04y and related superconducting and nonsuperconducting oxides between 500 and 5000 cm ' at room temperature. The growth in ir scattering with decreasing frequency is qualitatively explained by the anisotropic conductivity of these materials. Even at its peak ir value the effect is too small to alter significantly the optical constants obtained from specular reflectivity measurements.Since no additional scattering occurs near 0.5 eV, the absorption observed in sintered pellets at that energy cannot be associated with an anisotropic electronic excitation.