Alloying-Driven Phase Stability in Group-VB Transition Metals under Compression

Abstract:

The change in phase stability of Group-VB transition metals (V, Nb, and Ta) due to pressure and alloying is explored by means of first-principles electronic-structure calculations. It is shown that under compression stabilization or destabilization of the ground-state body-centered cubic (bcc) phase of the metal is mainly dictated by the band-structure energy. In the case of alloying the change in phase stability is defined by the interplay between the band-structure and Madelung energies. We show that band-structure effects determine phase stability when a particular Group-VB metal is alloyed with its nearest neighbors within the same d-transition series: the neighbor with less and more d electrons destabilize and stabilize the bcc phase, respectively. When V is alloyed with neighbors of a higher (4d- or 5d-) transition series, both electrostatic Madelung and band-structure energies stabilize the bcc phase. Utilizing the self-consistent ab initio lattice dynamics approach, we show that pressure-induced mechanical instability of bcc V, which results in formation of a rhombohedral (rh) phase at around 60-70 GPa at room temperatures, will prevail significant heating and compression. Furthermore, alloying with Cr decreases the temperature at which stabilization of the bcc phase occurs at elevated pressure.

• Periodical: Solid State Phenomena (Volume 258)
• Pages: 125-130
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.258.125
• Online since: December 2016
• Authors: Alexander Landa*, Per Söderlind
• Keywords: Alloys, Elevated Temperatures, High Pressures, Phase Transformation, Transition Metals

References

[1] Y. Ding, R. Ahuja, J. Shu, P. Chow, W. Luo and H. K. Mao: Phys. Rev. Lett. Vol. 98 (2007), p.085502.

[2] B. Lee, R. E. Rudd, J. E. Klepeis, P. Söderlind and A. Landa: Phys. Rev. Vol. B 75 (2007), p.180101(R).

[3] A. Landa, J. Klepeis, P. Söderlind, I. Naumov, O. Velikokhatnyi, L. Vitos and A. Ruban: J. Phys.: Condens. Matter Vol. 18 (2006), p.5079.

DOI: 10.1088/0953-8984/18/22/008

[4] A. Landa, J. Klepeis, P. Söderlind, I. Naumov, O. Velikokhatnyi, L. Vitos and A. Ruban: J. Phys. Chem. Sol. Vol. 67 (2006), p. (2056).

DOI: 10.1016/j.jpcs.2006.05.027

[5] L. Vitos: Computational Quantum Mechanics for Materials Engineers: The EMTO Method and Applications (Springer-Verlag, London 2007).

[6] J. P. Perdew, K. Burke and M. Ernzerhof: Phys. Rev. Lett. Vol. 77 (1995), p.3865.

[7] J. S. Faulkner: Prog. Mat. Sci. Vol. 27 (1982), p.1.

[8] L. Vitos, I. A. Abrikosov and B. Johansson: Phys. Rev. Lett. Vol. 87 (2001), p.156401.

[9] D. J. Chadi and M. L. Cohen: Phys. Rev. B Vol. 8, (1973) p.5747; S. Froyen: ibid. Vol. 39 (1989), p.3168.

[10] A. V. Ruban and H. L. Skriver: Phys. Rev. B Vol. 66 (2002), p.024201; A. V. Ruban, S. I. Simak, P. A. Korzhavyi and H. L. Skriver: ibid. Vol. 66 (2002), p.024202.

DOI: 10.1103/physrevb.66.024202

[11] I. A. Abrikosov, S. I. Simak, B. Johansson, A. V. Ruban and H. L. Skriver: Phys. Rev. B Vol. 56 (1997), p.9319.

[12] J. M. Wills, M. Alouani, P. Andersson, A. Delin, O. Eriksson and O. Grechnev: Full-Potential Electronic Structure Method (Springer-Verlag, Berlin 2010).

DOI: 10.1007/978-3-642-15144-6_7

[13] F. D. Murnaghan: Proc. Natl. Acad. Sci. Vol. 30 (1944), p.244.

[14] M. Mehl, B. M. Klein and D. A. Papaconstantopoulos, in: Intermetallic Compounds: Principles and Practice, Principles, edited by J. H. Westbrook and R. L. Fleisher, volume 1, Wiley London (1995), pp.195-210.

[15] P. Souvatzis, O. Eriksson, M. I. Katsnelson and S. P. Rudin: Phys. Rev. Lett. Vol. 100 (2008), p.095901; Comp. Mat. Sci. Vol, 44 (2009), p.888.

[16] A. Landa, P. Söderlind, A. V. Ruban, O. E. Peil and L. Vitos: Phys. Rev. Lett. Vol. 103 (2009), p.235501.

[17] A. Landa, P. Söderlind, O. I. Velikokhatnyi, I. I. Naumov, A. V. Ruban, O. E. Peil and L. Vitos: Phys. Rev. Vol. B 82 (2010), p.144114.

DOI: 10.1103/physrevb.82.144114

[18] A. Landa, P. Söderlind and L. H. Yang: Phys. Rev. Vol. B 89 (2014), p.020101(R).

[19] C. Dai, X. Jin, X. Zhou, J. Liu and J. Hu: J. Phys. D: Appl. Phys. Vol. 34 (2001), p.3064.