Details
| Original language | English |
|---|---|
| Pages (from-to) | 2093-2099 |
| Number of pages | 7 |
| Journal | Crystal Growth and Design |
| Volume | 18 |
| Issue number | 4 |
| Early online date | 7 Mar 2018 |
| Publication status | Published - 4 Apr 2018 |
Abstract
The defect density of a material is decisive for its physical, chemical, and mechanical properties. Accordingly, defect tuning is desirable for applications spanning, e.g., batteries, fuel cells, electronics, optics, catalysis, and mechanical strength and resilience. Here, we simulate the mechanochemical synthesis of the perovskite Ba1-xSrxLiF3 by compressing a BaLiF3 nanoparticle with a SrLiF3 nanoparticle under conditions likely to occur during high-energy ball milling. We investigate the crystallization process and the ionic mobility of the system and compare with experiment. Animations of the crystallization, simulated under high pressure, revealed that cations, within the crystallization front, would commonly condense onto "incorrect" lattice sites, in some cases eventually leading to the formation of anti-site defects. However, most of these cations would then re-amorphize and the "correct" cation would take its place - rectifying the defect. Crucially, it is the amorphous/crystalline interface that enables such repair because the ions are mobile in this region. The simulations reveal high ion mobility close to the anti-site defects and other defective regions, but no ion mobility in the defect free regions of BaLiF3. The MD simulations indicate that high-energy ball milling might reduce the anti-site defect density in a material by exposing these defects to the surface or creating amorphous regions within the crystallite which then would allow localized recrystallization, enabling defect repair. This assumption is a possible explanation for the reduced ion mobility, revealed by NMR spectroscopy, and, thus, most likely smaller defect density in BaLiF3 prepared by high-energy ball milling compared to thermally synthesized BaLiF3 samples.
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Crystal Growth and Design, Vol. 18, No. 4, 04.04.2018, p. 2093-2099.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Formation and Elimination of Anti-site Defects during Crystallization in Perovskite Ba1- xSrxLiF3
AU - Düvel, André
AU - Morgan, L. M.
AU - Chandran, C. Vinod
AU - Heitjans, Paul
AU - Sayle, D. C.
N1 - Funding Information: Financial support by the DFG, Germany, in the project DU 1668 1-1/1-2 is gratefully acknowledged. We are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which are partially funded by EPSRC (EP/P020194/1). A.D. thanks A. Kuhn for fruitful discussions.
PY - 2018/4/4
Y1 - 2018/4/4
N2 - The defect density of a material is decisive for its physical, chemical, and mechanical properties. Accordingly, defect tuning is desirable for applications spanning, e.g., batteries, fuel cells, electronics, optics, catalysis, and mechanical strength and resilience. Here, we simulate the mechanochemical synthesis of the perovskite Ba1-xSrxLiF3 by compressing a BaLiF3 nanoparticle with a SrLiF3 nanoparticle under conditions likely to occur during high-energy ball milling. We investigate the crystallization process and the ionic mobility of the system and compare with experiment. Animations of the crystallization, simulated under high pressure, revealed that cations, within the crystallization front, would commonly condense onto "incorrect" lattice sites, in some cases eventually leading to the formation of anti-site defects. However, most of these cations would then re-amorphize and the "correct" cation would take its place - rectifying the defect. Crucially, it is the amorphous/crystalline interface that enables such repair because the ions are mobile in this region. The simulations reveal high ion mobility close to the anti-site defects and other defective regions, but no ion mobility in the defect free regions of BaLiF3. The MD simulations indicate that high-energy ball milling might reduce the anti-site defect density in a material by exposing these defects to the surface or creating amorphous regions within the crystallite which then would allow localized recrystallization, enabling defect repair. This assumption is a possible explanation for the reduced ion mobility, revealed by NMR spectroscopy, and, thus, most likely smaller defect density in BaLiF3 prepared by high-energy ball milling compared to thermally synthesized BaLiF3 samples.
AB - The defect density of a material is decisive for its physical, chemical, and mechanical properties. Accordingly, defect tuning is desirable for applications spanning, e.g., batteries, fuel cells, electronics, optics, catalysis, and mechanical strength and resilience. Here, we simulate the mechanochemical synthesis of the perovskite Ba1-xSrxLiF3 by compressing a BaLiF3 nanoparticle with a SrLiF3 nanoparticle under conditions likely to occur during high-energy ball milling. We investigate the crystallization process and the ionic mobility of the system and compare with experiment. Animations of the crystallization, simulated under high pressure, revealed that cations, within the crystallization front, would commonly condense onto "incorrect" lattice sites, in some cases eventually leading to the formation of anti-site defects. However, most of these cations would then re-amorphize and the "correct" cation would take its place - rectifying the defect. Crucially, it is the amorphous/crystalline interface that enables such repair because the ions are mobile in this region. The simulations reveal high ion mobility close to the anti-site defects and other defective regions, but no ion mobility in the defect free regions of BaLiF3. The MD simulations indicate that high-energy ball milling might reduce the anti-site defect density in a material by exposing these defects to the surface or creating amorphous regions within the crystallite which then would allow localized recrystallization, enabling defect repair. This assumption is a possible explanation for the reduced ion mobility, revealed by NMR spectroscopy, and, thus, most likely smaller defect density in BaLiF3 prepared by high-energy ball milling compared to thermally synthesized BaLiF3 samples.
UR - http://www.scopus.com/inward/record.url?scp=85044960395&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.7b01552
DO - 10.1021/acs.cgd.7b01552
M3 - Article
AN - SCOPUS:85044960395
VL - 18
SP - 2093
EP - 2099
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 4
ER -