Ultrawide Temperature Range with Stable Permittivity and Low Dielectric Loss in (1 − x)[0.90Na0.5Bi0.5TiO3-0.10BiAlO3]-xNaNbO3 System

Abstract

High-temperature capacitors have become an important research topic recently as commercially available capacitors cannot fulfill the new requirements from industry. In this work, a new ceramic ternary system (1 − x)[0.9Na0.5Bi0.5TiO3-0.1BiAlO3]-xNaNbO3 is introduced, and the effects of NaNbO3 concentration on macroscopic phase structure, locally disordered structure, dielectric properties, conduction properties, and energy storage properties are studied. At the optimum composition of x = 0.30, an ultrawide temperature range (−90 and 320 °C) covering both stable permittivity (Δε′/ε′25°C ≤ ± 15%) and low dielectric loss (tan δ ≤ 0.02) can be obtained. Additionally, this material has a high RC constant of 2.8 s and a high energy storage efficiency of 88% under the electric field of 60 kV cm−1 at room temperature. Therefore, this work provides a very promising candidate for dielectrics used in multilayer ceramic capacitors (MLCC) in an ultrawide operating temperature range.