Improved Polarization Retention of BiFeO3 Thin Films Using GdScO3(110)Substrates

作     者：Shuai-Qi Xu Yan Zhang Hui-Zhen Guo Wen-Ping Geng Zi-Long Bai An-Quan Jiang 许帅骑;张岩;郭慧珍;耿文平;白子龙;江安全

作者机构：State Key Laboratory of ASIC and SystemSchool of MicroelectronicsFudan UniversityShanghai 200433 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2017年第34卷第2期

页      面：104-107页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Supported by the National Basic Research Program of China under Grant No 2014CB921004 the National Natural Science Foundation of China under Grant No 61225020 

主　　题：BFO GSO Improved Polarization Retention of BiFeO3 Thin Films Using GdScO3 Substrates SRO 110 

摘      要：Epitaxial ferroelectric one direction over the thin fihns on single-crystal substrates generally show a preferred domain orientation in other in demonstration of a poor polarization retention. This behavior will affect their application in nonvolatile ferroelectric random access memories where bipolar polarization states are used to store the logic 0 and 1 data. Here the retention characteristics of BiFe03 thin films with Srftu03 bottom electrodes on both GdSc03 （110） and SrTiO3 （100） substrates are studied and compared, and the results of piezoresponse force microscopy provide a long time retention property of the films on two substrates. It is found that bismuth ferrite thin films grown on GdScO3 substrates show no preferred domain variants in comparison with the preferred downward polarization orientation toward bottom electrodes on SrTi03 substrates. Tile retention test from a positive-up domain to a negative-down domain using a signal generator and an oscilloscope coincidentally shows bistable polarization states on the GdSeOa substrate over a measuring time of 500s, unlike the preferred domain orientation on SrTi03, where more than 65~o of upward domains disappear after 1 s. In addition, different sizes of domains have been written and read by using the scanning tip of piezoresponse force microscopy, where the polarization can stabilize over one month. This study paves one route to improve the polarization retention property through the optimization of the lattice-mismatched stresses between films and substrates.