Dilation of the α-Fe lattice by manganese

The dilation of the α-Fe lattice by manganese (0 to 2.4 at.%) has been determined by lattice parameter and density measurements at 25°C. The results may be described within experimental error by the linear expressions Q = Q_Fe−0.007₁ × (at.% Mn) g.cm⁻³ (density measurement) and a₀ = a_Fe + 0.0006₇ × (at.% Mn) Å (X-ray measurement). The virtual absence of dilation at Mn contents below 0.6at.%, reported in two previous investigations, is suggested as having resulted from internal oxidation of Mn.