摘要
研究了特异结构锆钛酸铅PbZr0.38Ti0.62O3(PZT)多层膜的铁电和介电特性.同均一相PZT薄膜材料相比,由致密层和多孔层交替排列形成的近周期PZT多层膜具有铁电、介电增强效应.在100V极化电压下,多层膜的平均剩余极化强度达42.3μC/cm2,矫顽场为43kV/cm.大的极化强度值归因于大的膜厚和多孔结构有效释放膜内张应力的结果.室温低频限下,PZT多层膜的表观相对介电常数超过2000.极为有趣的是,在所研究的频率范围,PZT多层膜具有两种截然不同的介电驰豫.低频介电损耗峰源自空间电荷极化;而遵从Arrhen ius律的高频介电响应可能同与氧空位VO¨相关的极性缺陷复合体有关.
Ferroelectric and dielectric properties of the PbZr0.38 Ti0.62 O3 （PZT） muhilayer with a unique structure were explored. Compared with the uniform PZT thin films, the PZT muhilayer with alternating dense-PZT and porous-PZT layers exhibits an enhancement both in ferroelectric and dielectric performances. The PZT multilayer has an average remanent polarization of 42.3C/cm^2 and an average coercive field of 43kV/cmunder an applied voltage of 100V. The large value of remanent polarization is attributed to the effective relaxation of the tensile stress in film due to large film thickness and por- ous structure. The apparently relative dielectric constant of the PZT muhilayer is more than 2000 at room temperature and low frequency limit. More interestingly, two distinct dielectric relaxations have been observed in the PZT multilayer in the investigated frequency range. The low-frequency loss peak originates from space charge polarization, while the high-frequency dielectric response following an Arrhenius-law is expected to be related to the dipolar defect complexes associated with oxygen vacancies Vo.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第3期169-171,184,共4页
Journal of Infrared and Millimeter Waves
基金
国家自然科学基金(60578058,10774154)
国家杰出青年基金(60225004)
上海市科技专项(0452nm085)
关键词
PZT多层膜
铁电
介电
极性缺陷复合体
PZT muhilayer
ferroelectric
dielectric
dipolar defect complex
