No long-range magnetic order in ε-iron down to 160 mK

Abstract

Epsilon-Fe, the high-pressure phase of elemental iron, is generally regarded as non-magnetic. However, theoretical predictions and experiments suggest that a residual magnetic moment exists, which might order at sufficiently low temperatures. Here, we report neutron diffraction data at 20 GPa down to 160 mK to probe this possibility. We find no magnetic long-range order under these conditions and no evidence for magnetic diffuse scattering, a result that considerably constrains the size of the magnetic moment, the nature of the putative magnetic order, and its stability range.