info:eu-repo/semantics/article
Electron paramagnetic resonance and positron annihilation study of the compensation mechanisms in donor-doped BaTiO3 ceramics
Fecha
2007-07Registro en:
Castro, Miriam Susana; Salgueiro, Walter Alberto; Somoza, Alberto Horacio; Electron paramagnetic resonance and positron annihilation study of the compensation mechanisms in donor-doped BaTiO3 ceramics; Pergamon-Elsevier Science Ltd; Journal of Physics and Chemistry of Solids; 68; 7; 7-2007; 1315-1323
0022-3697
CONICET Digital
CONICET
Autor
Castro, Miriam Susana
Salgueiro, Walter Alberto
Somoza, Alberto Horacio
Resumen
A study of the defect structure of BaTiO3-based ceramics and their correlation with the compensation mechanisms is presented. The addition of different Nb2 O5, Sb2 O3 or La2 O3 oxide contents (ranging from 0.05 to 0.60 mol%) to commercial BaTiO3 powders allowed to obtain the sintered specimens. EPR spectroscopy was used to characterize the paramagnetic species in the crushed samples. Information regarding bulk and vacancy-like defects in the studied specimens was also obtained using positron annihilation lifetime spectroscopy. Also, complementary analysis through tetragonality parameters and measurements on the real permittivity were carried out. The obtained results show a dependence of the defect profile of the BaTiO3-based specimens on the concentration and type of additive. For high additive content samples, titanium point-like defects were detected; while barium vacancies were detected in samples with low antimony content. Furthermore, oxygen vacancies were revealed in samples with low lanthanum addition. A relationship among the doping level and defect structure is proposed.