Details
Original language | English |
---|---|
Article number | 125135 |
Journal | Journal of Crystal Growth |
Volume | 523 |
Early online date | 24 Jun 2019 |
Publication status | Published - 1 Oct 2019 |
Abstract
Molten-flux synthesis was applied to the mixed ionic-electronic conducting oxide La2NiO4+δ. Melt of NaOH was used to dissolve precursors, which were either coarse mixtures of the oxides La2O3 and NiO from a classical solid-state route or ultrafine mixtures of La2CO5 and NiO from a sol-gel process. To estimate optimum synthesis temperature for the sol-gel process, reaction sequence was monitored by in-situ X-ray diffraction. The molten-flux synthesis in ambient air was conducted at 400 °C for up to 14 h with variation of additional water content and the precursor stoichiometry. Purity and composition of products were investigated by ex-situ X-ray diffraction and wavelength dispersive X-ray spectroscopy. A maximum length of plate-like crystals of ca. 30 μm in the a,b-plane was observed at a thickness of ca. 2 μm in the c-axis (i.e. aspect ratio of 15). By varying several parameters of the molten-flux synthesis, both size and aspect ratio of La2NiO4+δ plate-like crystals could be varied over a wide range.
Keywords
- A1. Crystal morphology, A2. Molten-flux, A2. Sol-gel synthesis, A2. Solid-state synthesis, B1. LaNiO, B2. Mixed ionic-electronic conductor
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Condensed Matter Physics
- Chemistry(all)
- Inorganic Chemistry
- Materials Science(all)
- Materials Chemistry
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In: Journal of Crystal Growth, Vol. 523, 125135, 01.10.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Anisotropic growth of La2NiO4+δ
T2 - Influential pre-treatment in molten-flux synthesis
AU - Hinterding, Richard
AU - Zhao, Zhijun
AU - Zhang, Chao
AU - Feldhoff, A.
N1 - Funding Information: This work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – FE 928/15-1 . Z. Zhao acknowledges financial support by the Graduate Academy of the Leibniz University Hannover. Authors gratefully appreciate technical assistance by F. Steinbach.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Molten-flux synthesis was applied to the mixed ionic-electronic conducting oxide La2NiO4+δ. Melt of NaOH was used to dissolve precursors, which were either coarse mixtures of the oxides La2O3 and NiO from a classical solid-state route or ultrafine mixtures of La2CO5 and NiO from a sol-gel process. To estimate optimum synthesis temperature for the sol-gel process, reaction sequence was monitored by in-situ X-ray diffraction. The molten-flux synthesis in ambient air was conducted at 400 °C for up to 14 h with variation of additional water content and the precursor stoichiometry. Purity and composition of products were investigated by ex-situ X-ray diffraction and wavelength dispersive X-ray spectroscopy. A maximum length of plate-like crystals of ca. 30 μm in the a,b-plane was observed at a thickness of ca. 2 μm in the c-axis (i.e. aspect ratio of 15). By varying several parameters of the molten-flux synthesis, both size and aspect ratio of La2NiO4+δ plate-like crystals could be varied over a wide range.
AB - Molten-flux synthesis was applied to the mixed ionic-electronic conducting oxide La2NiO4+δ. Melt of NaOH was used to dissolve precursors, which were either coarse mixtures of the oxides La2O3 and NiO from a classical solid-state route or ultrafine mixtures of La2CO5 and NiO from a sol-gel process. To estimate optimum synthesis temperature for the sol-gel process, reaction sequence was monitored by in-situ X-ray diffraction. The molten-flux synthesis in ambient air was conducted at 400 °C for up to 14 h with variation of additional water content and the precursor stoichiometry. Purity and composition of products were investigated by ex-situ X-ray diffraction and wavelength dispersive X-ray spectroscopy. A maximum length of plate-like crystals of ca. 30 μm in the a,b-plane was observed at a thickness of ca. 2 μm in the c-axis (i.e. aspect ratio of 15). By varying several parameters of the molten-flux synthesis, both size and aspect ratio of La2NiO4+δ plate-like crystals could be varied over a wide range.
KW - A1. Crystal morphology
KW - A2. Molten-flux
KW - A2. Sol-gel synthesis
KW - A2. Solid-state synthesis
KW - B1. LaNiO
KW - B2. Mixed ionic-electronic conductor
UR - http://www.scopus.com/inward/record.url?scp=85069577231&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2019.06.021
DO - 10.1016/j.jcrysgro.2019.06.021
M3 - Article
AN - SCOPUS:85069577231
VL - 523
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
M1 - 125135
ER -