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 |
|---|---|
| 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 |
Cite this
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Designer defect stabilization of the super tetragonal phase in >70-nm-thick BiFeO3 films on LaAlO3 substrates. / Sando, Daniel; Young, Thomas; Bulanadi, Ralph; Cheng, Xuan; Zhou, Yanyu; Weyland, Matthew; Munroe, Paul; Nagarajan, Valanoor.
In: Japanese Journal of Applied Physics, Vol. 57, No. 9, 0902B2, 01.09.2018.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Designer defect stabilization of the super tetragonal phase in >70-nm-thick BiFeO3 films on LaAlO3 substrates
AU - Sando, Daniel
AU - Young, Thomas
AU - Bulanadi, Ralph
AU - Cheng, Xuan
AU - Zhou, Yanyu
AU - Weyland, Matthew
AU - Munroe, Paul
AU - Nagarajan, Valanoor
PY - 2018/9/1
Y1 - 2018/9/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85053413791&partnerID=8YFLogxK
U2 - 10.7567/JJAP.57.0902B2
DO - 10.7567/JJAP.57.0902B2
M3 - Article
VL - 57
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
SN - 0021-4922
IS - 9
M1 - 0902B2
ER -