Temperature Stable Dielectric Properties in BaTiO ₃ –Bi(Mg _2/3 Nb _1/3 )O ₃ –NaNbO ₃ Solid Solution

Abstract

Abstract 0.5BaTiO 3 –(0.5– x )Bi(Mg 2/3 Nb 1/3 )O 3 – x NaNbO 3 ( x =0.1, 0.2 and 0.3) samples were processed via solid‐state sintering route. Phase identification of the samples showed the formation of a single‐phase cubic perovskite‐structure (space group Pm ‐3 m ) which was further confirmed using Raman spectroscopy. Microstructural analysis of the samples revealed some voids in the samples while grain size was observed to decrease with increasing NaNbO 3 concentration. The addition of NaNbO 3 shifted T m to below room temperature and the stability range of 0.5BaTiO 3 –0.5Bi(Mg 2/3 Nb 1/3 )O 3 ceramics was enhanced. The sample with x =0.20 exhibited ϵ r(mid) = 400 ±15% stable over a wide temperature range from −85 to 500 °C and most importantly a low dielectric loss of < 0.05 stable across a wide temperature range −100 to 426 °C was maintained. The thermally stable dielectric properties of sample x =0.2 suggests that it could be useful candidate material for capacitor applications in both low (X9R) as well as harsh environment applications.