X-ray and dielectric studies of ferroelectric phase in the Ba1-x(Yb0.5 Na0.5)x TiO3 system for low doping level

Ceramics of solid solution Ba1-x(Yb0.5Na0.5)xTiO3 were sintered in the temperature range 1220-1400°C. Dielectric properties of ceramics belonging to the whole composition domain were investigated in a broad range of temperatures (75-450 K) and frequencies (0.1-100 kHz). These ceramics were prepared using the conventional mixed-oxide technique. The temperature dependence of the dielectric constant of these ceramics were investigated. The rombohedral–orthorhombic and orthorhombic-quadratic perovskite transitions are characterized by two weak peaks but the tetragonal-cubic or ferroelectric- paraelectric one is characterized by a pronounced peak with weak frequency dispersion. Excellent dielectric properties have been obtained. The single phase of these prepared ceramics was characterizedby X-ray diffraction.