热压烧结对锆钛酸铅镧陶瓷电卡效应的影响  

Influence of Hot-press Sintering on Electrocaloric Effects of Lead Lanthanum Zirconate Titanate Ceramics

作　　者：王顺达[1] 朱定洋 曾亦可[1] 

机构地区：[1]华中科技大学光学与电子信息学院,武汉430074

出　　处：《硅酸盐学报》2015年第6期728-733,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(61378076)资助项目

摘　　要：探讨热压烧结工艺对PLZT(锆钛酸铅镧)陶瓷材料介电击穿性能、饱和极化强度以及电卡性能的影响。通过X射线衍射和扫描电子显微镜,分析陶瓷样品的相组成和微观结构。结果表明,热压烧结法有助于控制陶瓷晶粒的生长,提高陶瓷的致密度并增大陶瓷的介电击穿场强,从而有效提高陶瓷的电卡性能以及电卡转换效率。在328 K(55℃)与478 K(205℃)附近,分别发生低温铁电三方相到高温铁电三方相的相变(FRL-FRH)以及高温铁电三方相到立方顺电相(FRH-Pc)的相变,展现了比较好的弛豫性,在室温下达到3.6 K的绝热温变与1.8×0-7(K·m)/V的电卡转换效率,具有良好的电卡性能。The influence of hot-press sintering on the dielectric breakdown strength,polarization and electrocaloric effects of lead lanthanum zirconate titanate ceramics was investigated.The microstructure and phases of materials were characterized by scanning electron microscopy and X-ray diffraction.Compared to the conventional solid-state sintering method,hot-press sintering process can control the grain growth,and enhance the bulk density of the samples and the dielectric breakdown strength,thus effectively improving the electrocaloric effect and electrocaloric coefficients.At 328 K and 478 K,the phase transfers from low-temperature ferroelectric rhombohedral to high-temperature ferroelectric rhombohedral and from high-temperature ferroelectric rhombohedral to paraelectric phase,respectively,showing the superior dielectric relaxation properties.At room temperature,the samples fabricated by hot-press sintering method exhibit a good electrocaloric performance,i.e.,a large adiabatic temperature drop of 3.6 K and a great electrocaloric coefficient(|ΔT/ΔE|=1.8×10-7(K·m)/V).

关 键 词：铁电陶瓷 锆钛酸铅镧 电卡效应 

分 类 号：TQ174.1[化学工程—陶瓷工业]