High pressure synthesis and electrical properties of BaTiO3−xFx

摘要: The substitution of fluorine for oxygen in BaTiO3 was investigated by the reaction BaO2, BaF2, TiO2 and Ti under conditions 3.0 GPa 1300° C 2 H. Batio3−xFx solid solutions were obtained as a single phase region 0 ⩽x⩽0.1. X-ray diffraction data showed that symmetrical change from tetragonal to cubic form occurred atx=0.08 at room temperature. Also, characterized TG-DTA analysis, ESCA spectroscopy diffusion reflectance spectroscopy. As result, existence Ti3+ verified. electrical resistivities BaTiO3−xFx range 4Ωcm x=0.05 3OΩcm forx=0.1 300 K relationship between Inϱ 1000 T−1 linear. thermoelectric powers −250μV K−1 forx=0.05 −130μVK−1 forx=0.1. property solution discussed on basis conventional band model which involved localized donor levels associated with vacancies.