钛酸钡基铁电材料的介电非线性研究

通过A位或B位掺杂改性得到的钛酸钡基铁电材料,在外加直流偏置电场作用下,具有介电常数非线性可调的优异介电性能,可以广泛地应用于压控可调陶瓷电容器和微波可调器件领域。针对钛酸钡基铁电材料的介电非线性特性,讨论了BaTiO_3基铁电材料分别在铁电相、顺电相以及相转变温度场附近的介电非线性机理和相关理论;结合笔者近年来有关介电非线性研究的实验结果和相关文献报道,综述了不同A位离子(如Sr~(2-)和Ca~(2-)等)或B位离子(如Zr~(4 )和Sn~(4-)等)掺杂的BaTiO_3基铁电材料体系的介电非线性研究现状,分别对不同物质形态(陶瓷块体、薄膜和厚膜)的BaTiO_3基铁电材料的介电非线性研究及其应用进行了对比分析;并对钛酸钡基铁电材料今后的发展趋势和研究方向进行了展望。

RESEARCH ON DIELECTRIC NON-LINEARITY OF BaTiO_3-BASED FERROELECTRIC MATERIALS

BaTiO_3-based ferroelectric materials,which are modified by the substitution of A-site or B-site ions,can potentially be applied in voltage-controlled tunable ceramic capacitors and microwave devices due to their excellent dielectric nonlinearity under DC electric fields.In this paper,the mechanism of dielectric nonlinearity and relative theory of BaTiO_3-based ferroelectric materials in ferroelectric phase,paraelectric phase and the phase transformation process are discussed.According to our experimental results and related literatures,the dielectric nonlinearity and applications of BaTiO_3-based ferroelectric materials including ceramic blocks and thin and thick films are reviewed.Some technical problems in the research of dielectric non-linear ferroelectric materials are also discussed.