摘要
铁电材料钛酸钡(BaTiO3,简称BTO)与非铁电材料铝酸镧(LaAlO3,简称LAO)可以组成BTO/LAO铁电/非铁电超晶格。BTO/LAO超晶格的铁电、介电和热释电性能呈现新的变化特点。模拟计算了不同弛豫时间对不同层状周期结构的BTO/LAO超晶格介电性能的变化规律;分析了BTO/LAO超晶格中的弛豫机制、Debye弛豫效应与Maxwell-Wagner效应之间的关系。模拟计算表明BTO/LAO超晶格在厚度为0.8nm/0.8nm～1.6nm/1.6nm时介电常数出现极值,与实验结果符合较好。超晶格的界面电荷的累积对于弛豫时间的作用直接影响了BTO/LAO超晶格的介电性能;BTO/LAO超晶格的介质损耗主要来源于BTO/LAO超晶格的电导率。
Ferroelectric materials, BaTiO3 (abbr. BTO) , and non-ferroelectric materials, LaAlO3,(abbr. LAO) can compose the BTO/LAO superlattice. BTO/LAO superlattice shows the new variety of characteristics of it’s ferroelectric, dielectric and pyroelectric properties. Were simulated the change rules of dielectric constant of BTO/LAO superlattice with different stack periodicities under different relaxation time; were analyzed the relaxation mechanism, the relation between Debye relaxation & Maxwell-Wagner effect. The results of our simulation indicate that the BTO/LAO superlattice with the stack periodicities between 0.8 nm /0.8 nm to 1.6 nm / 1.6 nm show the extremes dielectric constant, which accords with the result of experimentation well. Results of this study revealed that the charge accumulation at discontinuous interfaces in superlattice would have a straight effect on dielectric properties of BTO/LAO superlattice; and the main origin of imaginary permittivity come from the conductance of BTO/LAO superlattice.
出处
《电子元件与材料》
CAS
CSCD
北大核心
2005年第4期5-8,共4页
Electronic Components And Materials
基金
国家重大基础研究项目(51310Z06–1)
