Oxygen vacancy generation in rare-earth-doped SrTiO3

Calculations of the energetics of rare-earth incorporation in SrTiO3 and other perovskite materials using classical potential models are widely featured in the literature. However, the standard incorporation mechanisms are often simplified and many do not account for the generation of oxygen vacancies. In this work, we use two mixed defect schemes that account for the introduction of rare-earth dopants at both the A- and B-sites of the perovskite structure and oxygen vacancies. An overall assessment of rare-earth doping in SrTiO3 using the standard dopant incorporation modes with respect to dopant ionic radii is also given. Although the energies for our proposed mixed mechanisms are somewhat higher than the energies for the standard mechanisms, they are more realistic when compared to real samples, as they incorporate a range of different intrinsic defects, unlike the idealized standard schemes. Strong binding energies are reported throughout, in agreement with previous studies. A comparative study of these mixed schemes in BaTiO3 and SrTiO3 reveals that they are more likely to be active in Ba TiO3.status: publishe