(Ba0.7Ca0.3)TiO3/Ba(Zr0.2Ti0.8)O3 铁电超晶格中内建电场的周期性依赖性。

Periodicity Dependence of the Built-in Electric Field in (Ba0.7Ca0.3)TiO3/Ba(Zr0.2Ti0.8)O3 Ferroelectric Superlattices.

机构信息

School of Materials Science and Engineering, The University of New South Wales , Sydney, New South Wales 2052, Australia.

Materials Engineering, The University of Queensland , Brisbane, Queensland 4072, Australia.

出版信息

ACS Appl Mater Interfaces. 2015 Dec 2;7(47):26301-6. doi: 10.1021/acsami.5b08943. Epub 2015 Nov 17.

DOI:10.1021/acsami.5b08943

PMID:26556506

Abstract

Symmetric ferroelectric superlattices consisting of (Ba0.7Ca0.3)TiO3 (BCT) and Ba(Zr0.2Ti0.8)O3 (BZT) layers were successfully grown on La0.7Sr0.3MnO3 electroded (001)-oriented SrTiO3 substrates by laser molecular beam epitaxy. With the monitor of reflective high-energy electron diffraction, the growth mode and rate were precisely controlled to realize the desired superlattice periodicity as confirmed by both X-ray diffraction and transmission electron microscopy results. The microscopic piezoelectric response and macroscopic ferroelectric properties were investigated as a function of periodicity of the BCTm/BZTm (m = 3, 5, 10, and 15 unit cells) superlattices. The existence of a built-in electric field was confirmed in all the superlattices and its strength was highly dependent on the periodicity. The excellent tunability of built-in electric field opens a path for designing microelectronic devices with various functionalities based on BCTm/BZTm superlattices.

摘要

由(Ba0.7Ca0.3)TiO3 (BCT) 和 Ba(Zr0.2Ti0.8)O3 (BZT) 层组成的对称铁电超晶格通过激光分子束外延成功地生长在 La0.7Sr0.3MnO3 电极化的 (001) 取向 SrTiO3 衬底上。通过反射高能电子衍射的监测，精确控制生长模式和速率，以实现所需的超晶格周期性，这一点通过 X 射线衍射和透射电子显微镜的结果得到了证实。研究了 BCTm/BZTm（m = 3、5、10 和 15 个单元）超晶格周期性的微观压电响应和宏观铁电性能。在所有超晶格中都证实了内置电场的存在，其强度高度依赖于周期性。内置电场的优异可调性为基于 BCTm/BZTm 超晶格设计具有各种功能的微电子器件开辟了道路。