MIDINFRARED AND NEAR-INFRARED PROPERTIES OF SRTIO3 FROM TRANSMISSION AND REFLECTION MEASUREMENTS

We measured transmittance and reflectance spectra of commercial SrTiO3 crystals in the infrared region (25-12 000 cm(-1)). The reflectance R (v) spectra confirm recent results. The transmittance T(v) spectra sho w that SrTiO, is transparent above 1000 cm(-1), while the model usuall y employed to describe the complex dielectric function of SrTiO3 predi cts a negligible transmittance in all the infrared region. By combinin g T(v) and R(v) spectra, we directly determine the frequency dependenc e of the refractive indices n and k which accounts for the spectra mea sured in the mid-infrared and near-infrared range. This result will be important for a correct analysis of the infrared spectra of films dep osited on SrTiO3. (C) 1996 American Institute of Physics.