High dielectric constant and good thermal stability from −55 °C to 450 °C in BaTiO3-based ceramics.

An ultrahigh-temperature X – R type dielectric material, BaTiO 3 –Na 0.5 Bi 0.5 TiO 3 –Nb 2 O 5 –ZnO–Glass with Sm 2 O 3 addition, was successfully prepared. The effects of Sm 2 O 3 content on the phase structure, dielectric and electric properties of ceramics were investigated. Sm ion can substitute for both Ti and Ba-sites, which leads to the decrease of spontaneous polarization and dipolar polarization. As a result, the temperature stability in ε r of sample is improved obviously. The 0.2 mol% Sm 2 O 3 -doped sample shows the optimal dielectric properties ( ε r =2458; tan δ =1.80%; ∆ C / C 20 °C <±15%, −55 °C to 450 °C), which satisfies EIA X – R specification. This material with particular focuses on enhancing the upper temperature limit to 450 °C, while still maintaining high dielectric constant. [ABSTRACT FROM AUTHOR]