skip to main content

SciTech ConnectSciTech Connect

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

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 ofmore » the decomposition temperature of this compound.« less
Authors:
 [1] ; ;  [1]
  1. Laboratoire des Multimateriaux et Interfaces, UMR CNRS no. 5615, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex (France)
Publication Date:
OSTI Identifier:
21494283
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 184; Journal 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.
Country of Publication:
United States
Language:
English
Subject:
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