Control of the doping sites of Ho3+ in BaTiO3 by a water-soluble precursor method

Abstract

Controlling the substitution sites of Ho3+ in BaTiO3 was demonstrated with a water-soluble precursor method in a relatively high concentration region. Ho3+ was added in three different manners to replace either Ba2+ or Ti4+, or both Ba2+ and Ti4+ as Ba1-xHox TiO3 (A-site substitution), Ba Ti1-xHoxO3-x/2 (B-site substitution) and Ba1-x/2Hox/2 Ti1-x/2Hox/2 O3 (A/B-sites substitution). The substitution sites were carefully investigated with X-ray diffraction, elemental mapping analysis, X-ray absorption fine structure analysis and the electric properties measurements. The results revealed the difference in the properties such as solubility, local environments around the lanthanides and electric properties depending on the substitution site, which indicated the successful control of the substitution sites simply with the starting composition of the solution. The compositional uniformity of the watersoluble precursor was advantageous in controlling the substitution sites of a rare-earth in BaTiO3.