We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Possible absence of critical thickness and size effect in ultrathin perovskite ferroelectric films.
- Authors
Gao, Peng; Zhang, Zhangyuan; Li, Mingqiang; Ishikawa, Ryo; Feng, Bin; Liu, Heng-Jui; Huang, Yen-Lin; Shibata, Naoya; Ma, Xiumei; Chen, Shulin; Zhang, Jingmin; Liu, Kaihui; Wang, En-Ge; Yu, Dapeng; Liao, Lei; Chu, Ying-Hao; Ikuhara, Yuichi
- Abstract
Although the size effect in ferroelectric thin films has been known for long time, the underlying mechanism is not yet fully understood and whether or not there is a critical thickness below which the ferroelectricity vanishes is still under debate. Here, we directly measure the thickness-dependent polarization in ultrathin PbZr0.2Ti0.8O3 films via quantitative annular bright field imaging. We find that the polarization is significantly suppressed for films <10-unit cells thick (∼4 nm). However, approximately the polarization never vanishes. The residual polarization is ∼16 μCcm−2 (∼17%) at 1.5-unit cells (∼0.6 nm) thick film on bare SrTiO3 and ∼22 μCcm−2 at 2-unit cells thick film on SrTiO3 with SrRuO3 electrode. The residual polarization in these ultrathin films is mainly attributed to the robust covalent Pb-O bond. Our atomic study provides new insights into mechanistic understanding of nanoscale ferroelectricity and the size effects.
- Publication
Nature Communications, 2017, Vol 8, Issue 6, p15549
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/ncomms15549