Effect of lanthanum doping on tetragonal-like BiFeO3 with mixed-phase domain structures

The recent discoveries of both chemical-driven and strain-driven morphotropic phase boundaries (MPBs) in BiFeO3 (BFO) thin films have opened up new horizons in developing high-performance lead-free piezoelectrics. An attempt to bridge these two MPBs is made by doping La into highly strained BFO thin...

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Bibliographic Details
Main Authors: You, Lu, Caesario, Petrus, Fang, Liang, Ren, Peng, Wang, Le, Zhou, Yang, Gruverman, Alexei, Wang, Junling
Other Authors: School of Materials Science & Engineering
Format: Journal Article
Language:English
Published: 2014
Subjects:
Online Access:https://hdl.handle.net/10356/103223
http://hdl.handle.net/10220/24412
Description
Summary:The recent discoveries of both chemical-driven and strain-driven morphotropic phase boundaries (MPBs) in BiFeO3 (BFO) thin films have opened up new horizons in developing high-performance lead-free piezoelectrics. An attempt to bridge these two MPBs is made by doping La into highly strained BFO thin films with the coexistence of tetragonal-like and rhombohedral-like phases. The structural, morphological, and ferroelectric properties of such films are investigated. It is observed that La doping changes the energy landscape between the tetragonal-like and the rhombohedral-like polymorphs due to the chemical pressure imposed by the La substitution. Polar instability is found upon increasing La doping for the in-plane polarization component, which correlates with the vanishing of in-plane ferroelectric domain structures. The transition sequence of the in-plane ferroelectric polarization resembles that previously reported for the bulklike rhombohedral phase of BFO under continuous La doping, indicating the universality of the chemical-alloying effect on the ferroelectric order.