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A Strain-Driven Antiferroelectric-to-Ferroelectric Phase Transition in La-Doped BiFeO3 Thin Films on Si.

Authors :
Deyang Chen
Nelson, Christopher T.
Xiaohong Zhu
Serrao, Claudy R.
Clarkson, James D.
Zhe Wang
Ya Gao
Shang-Lin Hsu
Dedon, Liv R.
Zuhuang Chen
Di Yi
Heng-Jui Liu
Dechang Zeng
Ying-Hao Chu
Jian Liu
Schlom, Darrell G.
Ramesh, Ramamoorthy
Source :
Nano Letters. Sep2017, Vol. 17 Issue 9, p5823-5829. 7p.
Publication Year :
2017

Abstract

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-phase). 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. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
15306984
Volume :
17
Issue :
9
Database :
Academic Search Index
Journal :
Nano Letters
Publication Type :
Academic Journal
Accession number :
125142967
Full Text :
https://doi.org/10.1021/acs.nanolett.7b03030