High pressure X-ray diffraction study of all Fe–Sn intermetallic compounds and one Fe–Sn solid solution

The present study describes the preparation of all five Fe–Sn intermetallic compounds, FeSn2, FeSn, Fe3Sn2, Fe5Sn3, and Fe3Sn, and the results of the X-ray diffraction study under static high pressure up to 25 GPa using nitrogen as a pressure-transmitting medium. The samples were prepared with phase purities of 97% and higher. Four Fe–Sn intermetallics, FeSn2, FeSn, Fe5Sn3, and Fe3Sn, show no phase transition to the highest pressure achieved; Fe3Sn2 undergoes two transitions to 25 GPa. The bulk moduli of these materials decrease approximately linearly with increasing Sn content, with the exception of Fe3Sn2. We also studied the solubility of Sn in α-Fe (α-Fe1−xSnx). Tin expands the α-Fe lattice according to Vegard's law to at least 6 at.% Sn. The solid solution α-Fe0.92Sn0.08 was examined beyond the pressure of the α/ɛ-phase transition. The onset of the phase transition in α-Fe0.92Sn0.08 occurs at about 24 GPa, higher than the transition pressure of 14 GPa in pure α-Fe, but at a similar lattice parameter, a ≈ 2.800 Å.