標題: A Strain-Driven Antiferroelectric-to-Ferroelectric Phase Transition in La-Doped BiFeO3 Thin Films on Si
作者: Chen, Deyang
Nelson, Christopher T.
Zhu, Xiaohong
Serrao, Claudy R.
Clarkson, James D.
Wang, Zhe
Gao, Ya
Hsu, Shang-Lin
Dedon, Liv R.
Chen, Zuhuang
Yi, Di
Liu, Heng-Jui
Zeng, Dechang
Chu, Ying-Hao
Liu, Jian
Schlom, Darrell G.
Ramesh, Ramamoorthy
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: BiFeO3;multiferroic;antiferroelectric;strain engineering;spin-charge-lattice coupling;antiferromagnetic
公開日期: 1-Sep-2017
摘要: A strain-driven orthorhombic (O) to rhombohedral (R) phase transition is reported in La-doped BiFeO3 thin films on silicon substrates. Biaxial compressive epitaxial strain is found to stabilize the rhombohedral phase at La concentrations beyond the morphotropic phase boundary (MPB). By tailoring the residual strain with film thickness, we demonstrate a mixed O/R phase structure consisting of O phase domains measuring tens of nanometers wide within a predominant R phase matrix. A combination of piezoresponse force microscopy (PFM), transmission electron microscopy (TEM), polarization electric field hysteresis loop (P-E loop), and polarization maps reveal that the O-R structural change is an antiferroelectric to ferroelectric (AFE-FE) phase transition. Using scanning transmission electron microscopy (STEM), an atomically sharp O/R MPB is observed. Moreover, X-ray absorption spectra (XAS) and X-ray linear dichroism (XLD) measurements reveal a change in the antiferromagnetic axis orientation from out of plane (R-phaSe) to in plane (O-p hase). These findings provide direct evidence of spin-charge-lattice coupling in La-doped BiFeO3 thin films. Furthermore, this study opens a new pathway to drive the AFE-FE O-R phase transition and provides a route to study the O/R MPB in these films.
URI: http://dx.doi.org/10.1021/acs.nanolett.7b03030
http://hdl.handle.net/11536/146084
ISSN: 1530-6984
DOI: 10.1021/acs.nanolett.7b03030
期刊: NANO LETTERS
Volume: 17
起始頁: 5823
結束頁: 5829
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