03. 01. 2006
D. Nguyen-Manh, A. P. Horsfield and S. L. Dudarev in: Phys. Rev. B 73, 020101(R) (2006) (4 pages)
We present an investigation of systematic trends for the self-interstitial atom (SIA) defect behavior in body-centered cubic (bcc) transition metals using density-functional calculations. In all the nonmagnetic bcc metals the most stable SIA defect configuration has the <111> symmetry. Metals in group 5B of the periodic table (V, Nb, Ta) have significantly different energies of formation of the <111> and <110> SIA configurations, while for the group 6B metals (Cr, Mo, W) the two configurations are linked by a soft bending mode. The relative energies of SIA defects in the nonmagnetic bcc metals are fundamentally different from those in ferromagnetic bcc alpha-Fe. The systematic trend exhibited by the SIA defect structures in groups 5B and 6B transition metals correlates with the observed thermally activated mobility of SIA defects.