复合钙钛矿弛豫铁电体中极化微区尺寸的确定  

Determining Size of Polar Microregions in Complex Perovskite Relaxor Ferroelectrics

作　　者：闫宗林[1] 姚熹[1] 张良莹[1] 

机构地区：[1]同济大学功能材料研究所,上海200092

出　　处：《压电与声光》2005年第6期665-667,共3页Piezoelectrics & Acoustooptics

基　　金：国家科技部"九七三"基金资助项目(2002CB613304)

摘　　要：通过分析极化微区形成过程中自由能的变化,确定极化微区的尺寸。以相变过程中的潜热做为均匀铁电体顺电态转变为铁电态自由能变化的近似值。随着温度降低,某些区域铁电态自由能密度降低;当铁电态自由能密度低于顺电态自由能密度时导致该区域出现极化,而晶格畸变在微区表面产生的弹性势能随着极化微区长大而逐渐增大,成为阻碍微区长大的主要原因。通过自由能极值分析,所得Pb(Mg1/3Nb2/3)O3-PbTiO3微区尺寸与实验结果相近。The size of the polar microregions was determined through analyzing their free energy change. The latent heat was used as the free energy change of uniform ferroelectrics in transition from paraelectric state to ferroelectrics state. The density of free energy in some regions decreases with decreasing temperature. When the densities of free energy in ferroelectrics state were lower than in paraelectric state, these regions are polarized. During the microregions grow, the elastic potential energy at their surface enhances, and that is the most important element that constrains the microregions growth. The calculated microregions sizes of Pb（Mg1/3 Nb2/3）O3-PbTiO3 were close to the experimental.

关 键 词：弛豫铁电体 极化微区尺寸 界面弹性势能 

分 类 号：TN304[电子电信—物理电子学]