Vacancy and doping driven ferromagnetism in BaTiO3 perovskite

Vacancy and doping induced magnetism in BaTiO3 perovskite is investigated by performing first-principles calculations. We demonstrate that all of the vacancies and doping induce ferromagnetism but by different mechanisms. Detailed electronic structure analysis revealed that the ferromagnetisms originate from the spin polarized Ti eg, O px, py and pz, N px and py, and Mn t2g for the O vacancy (VO), Ti vacancy (VTi), N substituting O (DN), and Mn substituting Ti (DMn), respectively. Either vacancy or doping in BaTiO3, exhibits half-metallic properties at O site, while reveals metallic properties at Ti site. The results presented here provide fundamental insights into the design of the multiferroics in conventional ferroelectrics.