Maghemite-like regions at the crossing of two antiphase boundaries in doped BiFeO3

December 2016

by J. M. Salih, L. Q. Wang, Q. M. Ramasse, L. Jones, J. Barthel, I. M. Reaney, A. J. Craven and I. MacLaren

Researchers from the University of Glasgow, STFC Daresbury Laboratories, the University of Oxford and the Ernst Ruska-Centre report on the observation of a novel structure at the point where two antiphase boundaries cross in a doped bismuth ferrite of composition (Bi_{0.85}Nd_{0.15})(Fe_{0.9}Ti_{0.1})O_{0.3}. The structure was investigated using a combination of high angle annular dark field imaging and electron energy loss spectroscopy spectrum imaging in the scanning transmission electron microscope.

A three-dimensional model was constructed by combining the position and chemistry data with previous results and assuming octahedral coordination of all Fe and Ti atoms. The resulting structure shows some novel L-shaped arrangements of iron columns, which are coordinated in a similar manner to FeO6 octahedra in maghemite. It is suggested that this may lead to local ferromagnetic orderings similar to those in maghemite.

Further reading:

J. M. Salih, L. Q. Wang, Q. M. Ramasse, L. Jones, J. Barthel, I. M. Reaney, A. J. Craven and I. MacLaren:
Maghemite-like regions at the crossing of two antiphase boundaries in doped BiFeO3
Materials Science and Technology 32 (2016) 242-247.