Conducting and Insulating Incorporation of Antimony into the BaTiO3 Lattice

Sb‐doped BaTiO3 is semiconducting only within a relative narrow concentration range. An explanation of this fact requires the knowledge of the lattice site occupied by the Sb. By means of X‐ray diffraction, neutron diffraction, and microprobe analysis it could be shown that Sb concentrations up to 10 at% are completely incorporated on Ti sites if an equivalent amount of Ti vacancies is offered, whereas the Sb substitutes Ba sites only partly even in the presence of an excess of TiO2. The Sb can cause conductivity in BaTiO3 only if it is incorporated on Ba sites. For this purpose a high excess of TiO2 is required. The transition from conducting to insulating incorporation is explained by a trapping mechanism caused by coupling of Sb with Ba vacancies taking into account the influence of the barrier layers.