La掺杂对PLZT压电陶瓷及PLZT/PVDF复合材料结构及特性的影响  

Effects of La Substitution on Structure and Characteristics of PLZT Ceramics and PLZT/PVDF Composites

作　　者：余仁安[1] 井晓静[1] 闵春英[1] 沈湘黔[1] 潘铁政 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212012 [2]攀特电陶科技有限公司,江苏昆山215300

出　　处：《硅酸盐学报》2011年第9期1451-1455,共5页Journal of The Chinese Ceramic Society

基　　金：中国博士后基金(20090451169);昆山市科技攻关基金(KC-0810)资助项目

摘　　要：分别采用固相反应烧结法和注模法制备(Pb1-xLax)(Zr0.5Ti0.5)1-x/4O3(x=0.01～0.13)锆钛酸铅镧(lead lanthanum zironate titanate,PLZT)压电陶瓷和0-3型PLZT/聚偏二氟乙烯(polyvinylidene fluoride,PVDF)复合材料。用X射线衍射表征PLZT陶瓷结构。用热膨胀系数突变法测量Curie温度,并研究PLZT陶瓷及其复合材料的介电与压电性能。结果表明:随着La掺量从0.01增加到0.13,PLZT陶瓷的四方度逐渐减小,四方相逐渐向三方相转变;同时Curie温度从356℃线性下降到28℃;相对介电常数和介电损耗则逐渐增大;压电应变系数和机电耦合系数呈先增大后减小的趋势,在x=0.07处取得极大值,分别为224 pC/N和0.5;随着PLZT陶瓷相Curie温度的下降及压电特性的变化,0-3型PLZT/PVDF复合材料的相对介电常数和压电应变系数呈逐渐上升趋势,其中压电应变系数从20 pC/N增大到34 pC/N,可归因于陶瓷相极化的改善。Lead lanthanum zirconate titanate（PLZT）（Pb1–xLax）（Zr0.5Ti0.5）1–x/4O3（x = 0.01–0.13） piezoelectric ceramics and polyvinylidene fluoride（0–3 PLZT/PVDF） composites were prepared by solid-state sintering process and casting process,respectively.The PLZT ceramic structure was investigated by X-ray diffraction,and the ceramics Curie temperature was determined by measuring critical expansion coefficient points.Dielectric and piezoelectric properties for PLZT ceramics and their composites were analyzed.Results show that,with La substitution content from 0.01 to 0.13,tetragonality of the PLZT ceramic decreases and tetragonal phase is gradually transformed into a rhombohedral phase,while Curie temperature drops almost linearly from 356 ℃ to room temperature.Electric properties are influenced by La substitution in the PLZT ceramic.With the increase of La substitution content,the relative dielectric constant and the dielectric loss exhibit an increasing tendency,while the piezoelectric coefficient and the electromechanical coupling coefficient initially increase and then decrease,achieving maximum values of 224 pC/N and 0.5 at x = 0.07,respectively.For the PLZT/PVDF composites,the relative dielectric constant and piezoelectric coefficient gradually increase with the La substitution content.Notably,the piezoelectric coefficient increased from 20 pC/N to 34 pC/N,which can be attributed to polarization enhancement for the PLZT ceramic phase in composite.

关 键 词：锆钛酸铅镧 CURIE温度 结构和特性 镧掺杂 

分 类 号：TB321[一般工业技术—材料科学与工程]