Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-27T01:36:43.356Z Has data issue: false hasContentIssue false
  • English
  • Français

A Combined Ab Initio and Bond-Order Potentials Study of Cohesion in Iridium

Published online by Cambridge University Press:  15 February 2011

Marc J. Cawkwell ,
Duc Nguyen-Manh ,
Vaclav Vitek  and
David G. Pettifor
Marc J. Cawkwell
Affiliation:
Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104-6272, U.S.A.
Duc Nguyen-Manh
Affiliation:
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, United Kingdom.
Vaclav Vitek
Affiliation:
Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut Street, Philadelphia, PA 19104-6272, U.S.A.
David G. Pettifor
Affiliation:
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, United Kingdom.
Get access

Abstract

The extremely high melting point and excellent resistance to oxidation and corrosion offered by iridium suggest numerous applications of this transition metal in static components at high temperatures and in aggressive environments. However, the mechanical and physical properties of f.c.c. Ir exhibit numerous anomalies when compared to other metals that crystallize in the f.c.c. structure. Notable examples include a negative Cauchy pressure, 1/2 (C12 – C44), brittle transgranular cleavage after a period of plastic flow even in pure single crystals and anomalous [ΆΆ0] branches in the phonon spectra. Atomistic studies of extended defects are needed to elucidate the origin of anomalous mechanical properties, such as brittleness. For this purpose we developed a Bond-Order Potential (BOP), an O(N) tight-binding formalism, employing physically transparent parameterizations that use experimental and ab initio data, generated in this study using the Full Potential Augmented Plane Wave plus Local Orbitals (APW+lo) method. The constructed BOP reproduces then both equilibrium as well as a variety of nonequilibrium properties of Ir and represents an excellent description of cohesion in f.c.c. Ir. This description of interatomic interactions is imminently suitable for studies of defects, such as dislocations and grain boundaries, that control plastic deformation and fracture.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 779: Symposium W – Multiscale Phenomena in Materials - Experiments and Modeling Related to Mechanical Behavior , 2003 , W5.5
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Yamabe-Mitari, Y., Ro, Y., Makuro, T. and Harada, H.. Metall. Mater. Trans. 29A, 537 (1998)Google Scholar
2. McKamey, C.G., George, E.P., Lee, E.H., Ohriner, E.K., Heatherly, J. and Cohron, J.W.. Scripta Mater. 42, 9 (2000)Google Scholar
3. Panfilov, P., Yermakov, A., Dmitriev, V. and Timofeev, N.. Platinum Metals Rev. 35, 196 (1991)Google Scholar
4. Yermakov, A., Panfilov, P. and Adamesku, R.. J. Mat. Sci. Letts. 9, 696 (1990)Google Scholar
5. Hecker, S.S., Rohr, D.L. and Stein, D.F.. Metall. Trans. A. 9, 481 (1978)Google Scholar
6. Panfilov, P., Novgorodov, V. and Yermakov, A.. J. Mat. Sci. Letts. 14, 137 (1994)Google Scholar
7. Znam, S., Nguyen-Manh, D., Pettifor, D.G. and Vitek, V.. Phil. Mag. A. 83, 415 (2003)Google Scholar
8. Heid, R., Bohnen, K-P, Felix, K., Ho, K.M. and Reichardt, W.. J. Phys.: Condens. Matter. 10, 7967 (1998)Google Scholar
9. Daw, M.S. and Baskes, M.I.. Phys. Rev. B. 29, 6443 (1984)Google Scholar
10. Finnis, M.W. and Sinclair, J.E.. Phil. Mag. A. 50, 45 (1984)Google Scholar
11. Horsfield, A.P., Bratkovsky, A.M., Fearn, M., Pettifor, D.G. and Aoki, M.. Phys. Rev. B. 53, 12694 (1996)Google Scholar
12. Mrovec, M.. PhD. Thesis. University of Pennsylvania (2002)Google Scholar
13. Girshick, A., Bratkovsky, A.M., Pettifor, D.G. and Vitek, V.. Phil. Mag. A. 77, 981 (1998)Google Scholar
14. Nguyen-Manh, D., Pettifor, D.G., Znam, S. and Vitek, V.. Mat. Res. Soc. Symp. Proc. Vol. 491, 353 (1998)Google Scholar
15. Nguyen-Manh, D., Pettifor, D.G., Cockayne, D.J.H., Mrovec, M., Znam, S. and Vitek, V.. Bull. Mater. Sci. 26, 43 (2003)Google Scholar
16. Sutton, A.P., Finnis, M.W., Pettifor, D.G. and Ohta, Y.. J. Phys. C.: Solid State Phys. 21, 35 (1988)Google Scholar
17. Goodwin, L., Skinner, A.J. and Pettifor, D.G.. Europhys. Letts. 9, 701 (1989)Google Scholar
18. Ducastelle, F. and Cyrot-Lackmann, F.. J. Phys. Chem. Sol. 31, 1295 (1970)Google Scholar
19. Lanczos, C.. J. Res. Natl. Bur. Stand. 45, 225 (1950)Google Scholar
20. Blaha, P.,Schwarz, K., Madsen, G.K.H., Kvasnicka, D. and Luitz, J., WIEN2k, An Augmented Plane Wave + Local Orbitals Program for Calculating Crystal Properties (Karlheinz Schwarz, Techn. Universität Wien, Austria), 2001. ISBN 3-9501031-1-2.Google Scholar
21. Perdew, J.P., Burke, K. and Ernzerhof, M.. Phys. Rev. Letts. 77, 3865 (1996)Google Scholar
22. Skriver, H.L.. Phys. Rev. B. 31, 1909 (1985)Google Scholar
23. Paidar, V., Wang, L.G., Sob, M. and Vitek, V.. Modelling Simul. Mater. Sci. Eng. 7, 369 (1999)Google Scholar
24. Nguyen-Manh, D., Pettifor, D.G. and Vitek, V.. Phys. Rev. Letts. 85, 4136 (2000)Google Scholar
25. Balk, T.J. and Hemker, K.J.. Phil. Mag. A. 81, 1507 (2001)Google Scholar
26. Gornostyrev, Yu.N., Katsnelson, M.I., Medvedeva, N.I., Mryasov, O.N., Freeman, A.J. and Trefilov, A.V.. Phys. Rev. B. 62, 7802 (2000)Google Scholar
27. Korzhavyi, P.A., Abrikosov, I.A., Johansson, B., Ruban, A.V. and Skriver, H.L.. Phys. Rev. B. 59, 11693 (1999)Google Scholar