Synthesis and structural characterization of Al{sub 4}Si{sub 2}C{sub 5}-homeotypic aluminum silicon oxycarbide, (Al{sub 6-x}Si{sub x})(O{sub y}C{sub 5-y}) (x{approx}0.8 and y{approx}1.6)

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.07.031· OSTI ID:21483674

Kaga, Motoaki; Urushihara, Daisuke; Iwata, Tomoyuki; Sugiura, Keita ^[1]; Nakano, Hiromi ^[2]; Fukuda, Koichiro ^[1]

---

1. Department of Environmental and Materials Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)
2. Cooperative Research Facility Center, Toyohashi University of Technology, Toyohashi 441-8580 (Japan)

We have prepared a new layered oxycarbide, [Al{sub 5.25(5)}Si{sub 0.75(5)}][O{sub 1.60(7)}C{sub 3.40(7)}], by isothermal heating of (Al{sub 4.4}Si{sub 0.6})(O{sub 1.0}C{sub 3.0}) at 2273 K near the carbon-carbon monoxide buffer. The crystal structure was characterized using X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The title compound is trigonal with space group R3m (centrosymmetric), Z=3, and hexagonal cell dimensions a=0.32464(2) nm, c=4.00527(14) nm and V=0.36556(3) nm{sup 3}. The atom ratios Al:Si were determined by EDX, and the initial structural model was derived by the direct methods. The final structural model showed the positional disordering of one of the three types of Al/Si sites. The reliability indices were R{sub wp}=4.45% (S=1.30), R{sub p}=3.48%, R{sub B}=2.27% and R{sub F}=1.25%. The crystal is composed of three types of domains with nearly the same fraction, one of which has the crystal structure of space group R3-bar m. The crystal structure of the remaining two domains, which are related by pseudo-symmetry inversion, is noncentrosymmetric with space group R3m. - Graphical Abstract: A new aluminum silicon oxycarbide, (Al{sub 6-x}Si{sub x})(O{sub y}C{sub 5-y}) (x{approx}0.8 and y{approx}1.6). The crystal is composed of three types of domains (I, II and III), and hence the structure is represented by a split-atom model. Individual crystal structures can be regarded as layered structures, which consist of A-type [(Al,Si){sub 4}(O,C){sub 4}] unit layers and B-type [(Al,Si)(O,C){sub 2}] single layers.

• OSTI ID: 21483674
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 9; Other Information: DOI: 10.1016/j.jssc.2010.07.031; PII: S0022-4596(10)00313-0; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM COMPOUNDS
CARBON
CARBON MONOXIDE
DOMAIN STRUCTURE
HEATING
LATTICE PARAMETERS
LAYERS
ORGANIC OXYGEN COMPOUNDS
SILICON COMPOUNDS
SPACE GROUPS
STRUCTURAL MODELS
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
TRIGONAL LATTICES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
MICROSCOPY
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SCATTERING
SPECTROSCOPY
SYMMETRY GROUPS