Wide temperature range of stable dielectric properties in relaxor BaTiO3-based ceramics by co-doping synergistic engineering

Abstract

Capacitor with good temperature stability is widely used in electronic devices. However, temperature stability suffers from limited improvement through traditional doping. In this study, the wide-temperature stability of BaTiO3-based ceramics is achieved by B site co-doping synergistic engineering. Element Ca is added to the ceramic to reduce the Curie temperature by optimizing the crystal structure, and subsequently, Nb is introduced to further suppress and broaden the dielectric peak by forming the core-shell structure. As excepted, 3%Nb doped 0.8BTC-0.2BMT ceramics possessed a temperature coefficient of capacitance at 25 °C (TCC25°C) being less than ±15% in the wide temperature range of −55 °C–180 °C, and an excellent energy storage density of 1.13 J cm−3. High dielectric constant (εr = 1076) and low dielectric loss (tanδ ∼ 0.06) meet the higher standards of the current capacitor industry, such as X8R requirements. This study provides a theoretical foundation for the design and preparation of high-performance dielectric materials.