偏压下弛豫型铁电陶瓷有效介电系数稳定方法的研究

STUDY OF STABILITY OF EFFECTIVE DIELECTRIC CONSTANT OF RELAXOR FERROELECTRICS UNDER BIASED VOLTAGE

本研究利用调整有效介电常数的互补公式［１］ 及Ｂ 位离子振动模型的位移公式［２］ ，导出了用于ＰＭＮ／ＰＺＮ／ＰＴ，ＰＭＮ／ＰＺＮ系铁电陶瓷稳定有效介电常数的经验公式：－ Ｔ－ Ｔ０２Ｔ－ Ｔ０１Ａ２ ＝ ｄ１ｄ２Ａ１ ． 用此式对ＰＺＮ，ＰＭＮ基铁电陶瓷偏压特性的研究，发现铁电陶瓷偏压下有效介电常数主要受其构型、Ａ 及Ｂ位离子的电负性差、添加剂的加权电负性差、宽容因子及其添加量的影响． 研究表明用此式对调整弛豫型铁电陶瓷的有效介电系数更加直观．

The empirical formula, -( T-T 02 )( T-T 01 ) A 2=d 1d 2A 1 ,is derived from complementary formula used for adjusting dielectric constant and displacement formula derived by vibration model of B-site ions,and the characteristics of ferroelectric PZN and PMN based ceramic materials under biased voltage were studied. It is found that the change of effective dielectric constant under biased voltage is related to structure of the materials, electric negative differences in A-site or B-site,the weighted average of electric negative differences and tolerant factors as well as amount of dopant. This formula is very effective for adjusting the dielectric constant of ferroelectric ceramics of PZN/PT and PMN/PZN/PT systems under biased voltage.