X-rays structural analysis and thermal stability studies of the ternary compound {alpha}-AlFeSi

Journal Article · Sun May 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.03.025· OSTI ID:21494283

Roger, J ^[1]; Bosselet, F; Viala, J C ^[1]

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1. Laboratoire des Multimateriaux et Interfaces, UMR CNRS no. 5615, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex (France)

From literature data presently available, the decomposition temperature and the nature of the decomposition reaction of the ternary compound {alpha}-AlFeSi (also designated as {alpha}{sub H} or {tau}{sub 5}) are not clearly identified. Moreover, some uncertainties remain concerning its crystal structure. The crystallographic structure and thermochemical behaviour of the ternary compound {alpha}-AlFeSi were meticulously studied. The crystal structure of {alpha}-AlFeSi was examined at room temperature from X-ray single crystal intensity data. It presents hexagonal symmetry, space group P6{sub 3}/mmc with unit cell parameters (293 K) a=12.345(2) A and c=26.210(3) A (V=3459 A{sup 3}). The average chemical formula obtained from refinement is Al{sub 7.1}Fe{sub 2}Si. From isothermal reaction-diffusion experiments and Differential Thermal Analysis, the title compound decomposes peritectically upon heating into {theta}-Fe{sub 4}Al{sub 13}(Si), {gamma}-Al{sub 3}FeSi and a ternary Al-rich liquid. Under atmospheric pressure, the temperature of this reversible transformation has been determined to be 772{+-}12 {sup o}C. -- Graphical abstract: Partial representation of the crystal structure of the {alpha}-Al{sub 7.1}Fe{sub 2}Si compound. Display Omitted Highlights: The main findings of our work are: {yields} a detailed X-rays crystal structure determination of the ternary compound {alpha}-AlFeSi. {yields} The precision of the silicon atoms positions in the crystal structure. {yields} A precised determination of the decomposition temperature of this compound.

• OSTI ID: 21494283
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 5; Other Information: DOI: 10.1016/j.jssc.2011.03.025; PII: S0022-4596(11)00122-8; Copyright (c) 2011 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
ALUMINIUM COMPOUNDS
ATMOSPHERIC PRESSURE
CRYSTALLOGRAPHY
DECOMPOSITION
DIFFERENTIAL THERMAL ANALYSIS
DIFFUSION
HCP LATTICES
HEATING
IRON COMPOUNDS
MONOCRYSTALS
SILICIDES
SOLID SOLUTIONS
SPACE GROUPS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 1000-4000 K
X RADIATION
CHEMICAL REACTIONS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DISPERSIONS
ELECTROMAGNETIC RADIATION
HEXAGONAL LATTICES
HOMOGENEOUS MIXTURES
IONIZING RADIATIONS
MIXTURES
RADIATIONS
SILICON COMPOUNDS
SOLUTIONS
SYMMETRY GROUPS
TEMPERATURE RANGE
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS