Europhys. Lett.
Volume 60, Number 2, October 2002
Page(s) 248 - 254
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 October 2002
DOI: 10.1209/epl/i2002-00356-y

Europhys. Lett., 60 (2) , pp. 248-254 (2002)

Tight-binding study of high-pressure phase transitions in titanium: Alpha to omega and beyond

M. J. Mehl and D. A. Papaconstantopoulos

Center for Computational Materials Science, Naval Research Laboratory Washington, D.C. 20375-5345, USA

(Received 29 May 2002; accepted 7 August 2002)

We use a tight-binding total-energy method, with parameters determined from a fit to first-principles calculations, to examine the newly discovered $\gamma$ phase of titanium. Our parameters were adjusted to accurately describe the $\alpha$Ti- $\omega$Ti phase transition, which is misplaced by density-functional calculations. We find a transition from $\omega$Ti to $\gamma$Ti at 102 GPa, in good agreement with the experimental value of 116 GPa. Our results suggest that current density-functional calculations will not reproduce the $\omega$Ti- $\gamma$Ti phase transition, but will instead predict a transition from $\omega$Ti to the bcc $\beta$Ti phase.

62.50.+p - High-pressure and shock-wave effects in solids and liquids.
64.70.Kb - Solid-solid transitions.
61.66.Bi - Elemental solids.

© EDP Sciences 2002