Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter December 29, 2021

On the Hypothesis of Bonding Related Atomic Ordering in Binary Omega Phases

  • Gabriel Julio Cuello , Armando Fernández Guillermet and José Rolando Granada

Abstract

A new model describing the structural and bonding properties of the omega phase in Zr–Nb alloys has recently been presented [G. B. Grad et al.: Z. Metallkd. 87, (1996) 726]. This model, which was aimed at explaining the composition dependence of the bonding distances, predicts that the omega phase in Zr–Nb alloys is ordered, i.e., that some of the crystallographic sites are preferently occupied for Zr atoms. This feature of the omega phase is not contradicted by the most recent studies of the lattice parameters, but it has not yet been tested against direct measurements of the atomic ordering. In this paper we identify, theoretically, the Bragg reflections that appear only if the alloy is ordered, and show that among the three prototypical isoelectronic systems Ti–V, Zr–Nb and Hf–Ta, the former is the most suitable one for an experimental test of the model. The use of neutron scattering and transmission experiments is critically discussed, and the optimum composition for experiments with Ti–V alloys is presented.


G. J. Cuello Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científicas Serrano 123 Madrid E-28006, Spain
A. Fernández Guillermet, J. R. Granada Centro Atómico Bariloche Consejo Nacional de Investigaciones Científicas y Técnicas Bustillo 9500 8400 Bariloche, Argentina

Dedicated to Professor Dr. rer nat. Gerhard Inden on the occasion of his 60th birthday


  1. It is a privilege for the authors to dedicate this work to Prof. inden on the occasion of his 60th birthday. One of us (AFG) has benefited over the years from stimulating conversations with Prof.Inden about various aspects of the phase stability problem.

    This work is part of a research project supported by CONICET (Argentina) under grant PIA 6100/96, by Fundación Antorchas (Argentina) under grant A-13434/1-000081, by Cooperativa de Electricidad Bariloche, and by Fundación Balseiro (Bariloche, Argentina).

Literature

1 Donohue, J.: The Structures of the Elements, Krieger Pub. Co. Malabar, Florida (1982).Search in Google Scholar

2 Xia, H.; Parthasarathy, G.; Luo, H.; Vohra, Y. K.; Ruoff, A. L.:Phys. Rev. B 42 (1990) 6736.10.1103/PhysRevB.42.6736Search in Google Scholar

3 Xia, H.; Duclos, S. J.; Ruoff, A. L.; Vohra, Y. K.: Phys. Rev. Lett. 64 (1990) 204.10.1103/PhysRevLett.64.204Search in Google Scholar

4 Ahuja, R.; Wills, J. M.; Johansson, B.; Eriksson, O.: Phys. Rev. B48 (1993) 16269.10.1103/PhysRevB.48.16269Search in Google Scholar

5 Grad, G. B.; Fernández Guillermet, A.; Pieres, J. J.; Cuello, G. J.:Z. Metallkd. 87 (1996) 721.Search in Google Scholar

6 Grad, G. B.; Fernández Guillermet, A.; Granada, J.R.:Z. Metallkd. 87 (1996) 726.Search in Google Scholar

7 Sikka, S. K.; Vohra, Y K.; Chidambaram, R.: Prog. Mater. Sci. 27(1982) 245.10.1016/0079-6425(82)90002-0Search in Google Scholar

8 Cuello, G. J.; Fernández Guillermet, A.; Grad, G. B.; Mayer, R. E.; Granada, J. R.: J. Nucl. Mater. 218 (1995) 236.10.1016/0022-3115(94)00437-4Search in Google Scholar

9 Grad, G. B.; Pieres, J. J.; Fernández Guillermet, A.; Cuello, G. J.; Granada, J. R.; Mayer, R. E.: Physica B 213 & 214 (1995) 433.10.1016/0921-4526(95)00180-HSearch in Google Scholar

10 Grad, G. B., Pieres, J. J.; Fernández Guillermet, A.; Cuello, G. J.;Mayer, R. E.; Granada, J. R.: Z. Metallkd. 86 (1995) 395.Search in Google Scholar

11 Pearson, W. B.: Proc. Roy. Soc. London Ser. A 365 (1979) 523.10.1098/rspa.1979.0032Search in Google Scholar

12 Pauling, L.: J. Amer. Chem. Soc. 69 (1947) 542.10.1021/ja01195a024Search in Google Scholar

13 Jamieson, J. C.: Science 140 (1963) 72.10.1126/science.140.3562.72Search in Google Scholar

14 Garcés, J. E.; Grad, G. B.; Fernández Guillermet, A.; Sferco, S.:sub mitted to J. Alloys Comp. (1998).Search in Google Scholar

15 See for example, G. L. Squires, Introduction to the Theory of Thermal Neutron Scattering, Cambridge University Press, Cambridge (1978).Search in Google Scholar

16 See for example, N. W. Ashcroft and N. D. Mermin, Solid State Physics, Holt, Rinehart and Winston, New York (1976), 104–108.Search in Google Scholar

17 Kropff, F.; Granada, J. R., Mayer, R. E.: Nucl. Instr. Meth. 198(1982) 515.10.1016/0167-5087(82)90293-9Search in Google Scholar

18 Mughabghab, S. F.: Neutron Cross Sections, Academic Press, New York (1984); for a summary of low-energy neutron scattering lengths and cross sections, see Table 1.1 in Ref. [21] or Table 2.2 in M. Bée, Quasielastic Neutron Scattering, Adam Hilger, Bristol (1988).Search in Google Scholar

19 Placzek, G.; Van Hove, L.: Nuov. Cim. 1 (1955) 233.10.1007/BF02731767Search in Google Scholar

20 Granada, J. R.: Z. Naturforsch. 39a (1984) 1160.10.1515/zna-1984-1202Search in Google Scholar

21 Lovesey, S. W.: Theory of Neutron Scattering from Condensed Matter, Vol. 1, Clarendon Press, Oxford (1984).Search in Google Scholar

Received: 1998-09-08
Published Online: 2021-12-29

© 1998 Carl Hanser Verlag, München

Downloaded on 29.3.2024 from https://www.degruyter.com/document/doi/10.3139/ijmr-1998-0160/html
Scroll to top button