Ultra‐Wide Temperature Stable Dielectrics Based on Bi 0.5 Na 0.5 TiO ₃ –NaNbO ₃ System

The microstructure, phase structure, ferroelectric, and dielectric properties of (1− x )Bi 0.5 Na 0.5 TiO 3 ‐ x NaNbO 3 [(1− x ) BNT ‐ x NN] ceramics conventionally sintered in the temperature range of 1080°C–1120°C were investigated as a candidate for capacitor dielectrics with wide temperature stability. Perovskite phase with no secondary impurity was observed by XRD measurement. With increasing NN content, (1− x ) BNT ‐ x NN was found to gradually transform from ferroelectric ( x = 0–0.05) to relaxor ( x = 0.10–0.20) and then to paraelectric state ( x = 0.25–0.35) at room temperature, indicated by P – I – E loops analysis, associated with greatly enhanced dielectric temperature stability. For the samples with x = 0.25–0.35, the temperature coefficient of capacitance ( TCC ) was found <11% in an ultra‐wide temperature range of −60°C–400°C with moderate dielectric constant and low dielectric loss, promising for temperature stable capacitor applications.