Field-induced Strain and Polarization Switching Mechanisms in Ba-modified PMN-PT Ceramics

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J. Korean Ceram. Soc. > Volume 37(1); 2000 > Article

Journal of the Korean Ceramic Society 2000;37(1): 12.

Ba 변성 PMN-PT계 강유전체의 전계유기변위와 분극특성

장명철

군산대학교 공과대학 재료공학과

Field-induced Strain and Polarization Switching Mechanisms in Ba-modified PMN-PT Ceramics

ABSTRACT

Dielectric property of Ba-modified 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 ceramics having compositions near the morphotropic phase boundary was investigated. For the specimens having Ba contents between 0 and 20 at%, the average transition temperature was decreased linearly with increasing Ba contents and the degree of hysteresis was also decreased with increasing Ba contents. The maximum dielectric constants (K), electric field induced polarization(P) and electrically-induced strain(S) were found to exihibit a maximum value at∼3 at% of Ba. The increase of S and the decrease of hysteresis by minor additions of Ba impurities indicated the development of new higher perfomance actuator materials. The composition of Ba-PMN-PT (10/65/35) may be appropriate for capacitor materials because of low hysteresis and high polarization.

Key words: Relaxor, Dielectric property, Polarization, Strain, PMN, Ba doping