Low temperature equation of state of iron

Abstract

The theoretical description of the electronic properties of iron under pressure involves the strong electronic correlations in this metal. We provide here reference structural data which can be used for this description. These data have been collected at low to ambient temperature in diamond anvil cells, under quasi-hydrostatic compression, using X-ray diffraction. The compression curves of α-Fe and ϵ-Fe have been measured up to 99.5 GPa along an isotherm at 15 K and the thermal expansion of ϵ-Fe has been measured between 15 K and 300 K at ∼57 GPa. The theoretical framework used in the literature which reproduces at best the compression curve of ϵ-Fe is dynamical mean field theory. The current measurements do not evidence any electronic topological transition in the scanned pressure range, where ϵ-Fe exhibits the behaviour of a Debye solid.