Carbon at the Ti site in strontium titanate from first principles

Perovskite oxides have attracted both experimental and theoretical attention due to their high permittivities, with SrTiO₃ used in waveguides, high capacity computer memory cells and dielectrics. Different growth methods yield various qualities of material, and thin-films growth using organic precursors makes carbon contamination highly probable. Using density functional theory we have calculated the electronic structure and vibrational properties of carbon substituting for Ti in cubic SrTiO₃. We find a relatively modest impact upon the electronic structure, with predicted impact upon observable factors, particularly the vibrational spectra and dielectric constant.