Journal
ACTA MATERIALIA
Volume 82, Issue -, Pages 356-368Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2014.09.003
Keywords
Bismuth ferrite; Crystal growth; High-resolution electron microscopy; Atomic structure; First-principles calculations
Funding
- National Natural Science Foundation of China [51390472]
- DFG [SFB 762]
- Czech Science Foundation [P204/11/P339]
- NSF [0722625]
- [NSF-DMR-1066158]
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [1066158] Funding Source: National Science Foundation
Ask authors/readers for more resources
We report on an investigation of state-of-the-art flux-grown multiferroic bismuth ferrite (BiFeO3; BFO) single crystals by transmission electron microscopy and electron diffraction. The crystals were pre-characterized by piezoresponse force microscopy, electrical resistance and superconducting quantum interference device magnetization measurements. The structurally highly perfect crystals show a ferroelectric stripe domain structure characterized by a domain width of 55 nm. Inside these domains an additional contiguous nanodomain substructure occurs, consisting of 180 degrees related domains, giving rise to satellite reflections at g {1/2 1/2 1/2}-type positions along < 110 > directions in the electron diffraction pattern corresponding to a characteristic length in real space of 15.5 nm. Furthermore, we present the first atomic-resolution study on the short-range order by aberration-corrected transmission electron microscopy in which all atoms including oxygen are imaged directly. By measuring the -Fe-O-Fe- atom topology, bond angles and atomic distances we derive the electrical dipole moment as well as the magnitude of the magnetic moment on the unit-cell level. The results evidence substantial atomic- to nano-scale disorder. Both the nanodomain substructure as well as the disorder should affect the subtle magnetoelectric interactions in this material and thereby impede the formation of long-range cycloidal spin ordering which up to now was considered an intrinsic feature of the magnetic properties of BiFeO3 single crystals. By Monte Carlo simulation on the basis of a state-of-the-art effective Hamiltonian we scrutinize certain aspects of the phase formation behavior in the BFO system forming the background of single-crystal growth. This study reveals a very sluggish phase evolution behavior, which should make it invariably difficult to obtain structurally fully equilibrated single crystals. (C)2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available