Figure 1. The calculated temperature effect on the surface energy and surface stress of the (110) and (001) facets of bcc Fe.

Experimental surface energies of δ Fe were reported by Price et al.¹⁴, and the available surface tension measurements (γ_LV) of liquid Fe were reviewed by Allen¹³. The surface energy at T_m was estimated by Tyson et al.¹² and at 0 K by Tyson et al.¹² and de Boer et al.¹⁹. The latter two 0 K estimates amended by the missing magnetic contribution are also plotted and discussed in the text. Data from refs ¹²,¹⁴,¹⁹ should be understood as to represent an average surface facet. Lines guide the eye. We estimate the error of the computed surface energy (surface stress) at 0 K and T_m to <0.1 J/m² (<0.2 J/m²) and 0.1–0.2 J/m² (0.3–0.4 J/m²), respectively.