During the last decades, increasing progresses have been made on the theoretical study of ferroelectric materials since the discovery of the barium titanate system (BaTiO3). Such advances are mainly due to the development of new theoretical approaches based on quantum mechanics, which have been complemented by the implementation of new, and more efficient, software and the rapid advance in the development of more powerful hardware. The ab-initio methods are approximations based on the Schrodinger’s equation of quantum mechanics, which takes into account only fundamental physical constants, one of them being the Density Functional Theory (DFT). The DFT is a method, which allows to solve, in a self-consistent way, the well known Kohn-Sham equation by using an exchange and correlation potential. This work aims the study of the electronics properties of the perovskite oxide based on BaTiO3, considering the inclusion of rare-earth ions as impurities into the structure. By using first-principles calculations and the DFT method, the presence of defects such as vacancies and dopants, as well as their influence on the physical properties, will be investigated.
The authors would like to thank to FAPEMIG, CAPES and CNPq Brazilian agencies for financial support. A. P. Aslla-Quispe also thanks to PAEC-OEA/GCUB nº 001/2015 for the financial support.