Structure of iron-rich compounds in the Yb-Fe-Al and Yb-Fe-Ga systems.

Radovan Cerny 

University of Geneva, 24 quai Ernest-Ansermet, Geneva 1211, Switzerland


Iron-rich rare-earth transition-metal alloys are of interest as constituents for permanent magnets. Ytterbium containing materials have not yet been studied in great detail because of problems with sample preparation. Our recent X-ray diffraction studies on single crystals [1,2] and powders [3] having compositional ratios close to Yb/(Fe,Al) or Yb/(Fe,Ga)=2/17 revealed four distinctly different structures, two having hexagonal symmetry (LuFe9.5 and TbCu7 type) at low and intermediate Al or Ga and Yb contents, respectively, and two having rhombohedral symmetry (PrFe7(A) and PrFe7(A+B) types) at high Al or Ga and Yb contents. All have a common hexagonal TbCu7 type subcell and contain chains made up of Yb and Fe(Al)2 or Fe(Ga)2 dumbbells running along the c-axis that substitute for each other with various ordering schemes and concentrations. The subcell ratio c/a depends on both the concentration of the dumbbells, for which it generally increases, and the structure type (dumbbell order). We define an order parameter capable of describing the dependency of the subcell ratio c/a on the Fe(Al)2 or Fe(Ga)2 dumbbell ordering, irrespective of structure type, as the probability of finding two dumbbells within a chain that are separated by one Yb atom only.

[1] Cerny R., Pacheco V., Yanson T., Manyako M. and Bodak O.: Z. Kristallographie, 218 (2003) 802-810

[2] Filinchuk Ya. E., Birkedal H., Cerny R., Hostettler M., Yanson T.I., Bodak O.I. and Yvon K.: Chemistry – A European Journal, 10 (2004) 2972-2976

[3] Bodak O., Tokaychuk Y., Manyako M., Pacheco V., Cerny R. and Yvon K.: J. Alloys and Compounds 354 (2003) L10-L15

Legal notice
  • Legal notice:

    Copyrighted materials, (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced, stored in or introduced into a retrieval or caching system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), or for any purpose, without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: must be provided.


Related papers
  1. Characterization of Metal Hydrides by Powder Diffraction
  2. Long and short range order in Laves phase deuterides
  3. Nonaqueous approach to a metal-organic framework: A new vanadium-oxobenzoate as case study

Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium B, by Radovan Cerny
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-11 11:59
Revised:   2009-06-07 00:44
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine