Superior polarization retention through engineered domain wall pinning

Dawei Zhang, Daniel Sando, Pankaj Sharma, Xuan Cheng, Fan Ji, Vivasha Govinden, Matthew Weyland, Valanoor Nagarajan, Jan Seidel

Research output: Contribution to journalArticleResearchpeer-review

7 Citations (Scopus)

Abstract

Ferroelectric materials possess a spontaneous polarization that is switchable by an electric field. Robust retention of switched polarization is critical for non-volatile nanoelectronic devices based on ferroelectrics, however, these materials often suffer from polarization relaxation, typically within days to a few weeks. Here we exploit designer-defect-engineered epitaxial BiFeO3 films to demonstrate polarization retention with virtually no degradation in switched nanoscale domains for periods longer than 1 year. This represents a more than 2000% improvement over the best values hitherto reported. Scanning probe microscopy-based dynamic switching measurements reveal a significantly increased activation field for domain wall movement. Atomic resolution scanning transmission electron microscopy indicates that nanoscale defect pockets pervade the entire film thickness. These defects act as highly efficient domain wall pinning centres, resulting in anomalous retention. Our findings demonstrate that defects can be exploited in a positive manner to solve reliability issues in ferroelectric films used in functional devices.

Original languageEnglish
Article number349
Number of pages8
JournalNature Communications
Volume11
Issue number1
DOIs
Publication statusPublished - 17 Jan 2020

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