Abstract
The stability of the “T-like” (T$) phase in BiFeO3 films grown on LaAlO3(001) is investigated. We show that the T$ phase can be stabilized for thicknesses >70nm under ultralow incident flux conditions in pulsed laser ablation growth. This low flux results in a low growth rate; thus, the sample is held at high temperatures (>600°C) for much longer than is typical. Transmission electron microscopy and X-ray diffraction analysis suggest that such growth conditions favor the formation of nanoscale “defect pockets”, which apply a local compressive strain of >1.8%. We propose that the cumulative effect of local stresses induced by such “designer defects” maintains macroscale strain coherence mechanical boundary conditions, which then preserves the T$ phase to thicknesses beyond conventional wisdom. Finally, by intentionally introducing an amorphous phase at the film-substrate interface, it is shown that the mixed-phase proportion can be tuned for a given thickness.
Original language | English |
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Article number | 0902B2 |
Number of pages | 7 |
Journal | Japanese Journal of Applied Physics |
Volume | 57 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1 Sep 2018 |
Equipment
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Centre for Electron Microscopy (MCEM)
Peter Miller (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility