Excellent high-temperature dielectric stability of BNT-based ceramics modified by NaNbO3

In this work, (1-x)(K0.5La0.5)0.1Ba0.054(Bi0.5Na0.5)0.846Ti0.95(Cr0.5Ta0.5)0.05O3- xNaNbO3 (replaced by (1-x)KLBBNT-xNN) (x = 0.02, 0.04, 0.06, 0.08, 0.1) ceramics were fabricated by conventional solid-state reaction route. As the content of NaNbO3 increasing, an excellent dielectric temperature stability with a permittivity ∼2583 is obtained in the ceramic samples with x = 0.06. The temperature coefficient of capacitance (TCC) for x = 0.06 sample is less than ± 15% in the range of 58 °C to 338 °C. The XRD and temperature dependent permittivity results indicated that the large permittivity with excellent dielectric temperature stability maybe caused by NaNbO3 doping, which reduces the relaxation phase transition temperature of BNT-based ceramics and expands the temperature range of dielectric temperature stability. This work provides a new method to obtain BNT-based ceramic capacitors with large and stable dielectric constant in a wide temperature range.