Incorporation of Aliovalent Dopants into the Bismuth-Layered Perovskite-Like Structure of BaBi4Ti4O15 |
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Authors: | Darko Makovec Irena Priboic Zoran Samardija Miha Drofenik |
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Affiliation: | Ceramics Department, Jožef Stefan Institute, Ljubljana, Slovenia |
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Abstract: | The solid solubility of the aliovalent dopants Fe3+ and Nb5+ in the BaBi4Ti4O15 compound, a member of the family of Aurivillius bismuth-based layer-structure perovskites, has been studied using quantitative wavelength-dispersive spectroscopic microanalysis (SEM/EPMA) in combination with X-ray powder diffractometry (XRPD). The samples with nominal (starting) compositions corresponding to the chemical formulas BaBi4Ti4–4 X Fe4 X O15 and BaBi4Ti4–4 X Nb4 X O15 were prepared by hot forging a mixture of BaTiO3 and Bi4Ti3O12 with additions of Fe2O3 or Nb2O5 followed by a long annealing at 1100°C. The study showed that an excess charge introduced into the structure by the substitution of Ti4+ ions with aliovalent dopants was preferentially compensated by a change in the ratio of Ba2+ to Bi3+ ions in the host structure according to the general formulas of the solid solutions Ba1–4 X Bi4+4 X Ti4–4 X Fe'4 X O15 and Ba1+4 X Bi4–4 X Ti4–4 X Nb·4 X O15. |
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Keywords: | dopants/doping perovskites ferroelectricity/ferroelectric materials |
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