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

Abstract

Abstract The present study describes the preparation of all five Fe–Sn intermetallic compounds, FeSn 2 , FeSn, Fe 3 Sn 2 , Fe 5 Sn 3 , and Fe 3 Sn, 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, FeSn 2 , FeSn, Fe 5 Sn 3 , and Fe 3 Sn, show no phase transition to the highest pressure achieved; Fe 3 Sn 2 undergoes two transitions to 25 GPa. The bulk moduli of these materials decrease approximately linearly with increasing Sn content, with the exception of Fe 3 Sn 2 . We also studied the solubility of Sn in α-Fe (α-Fe 1− x Sn x ). Tin expands the α-Fe lattice according to Vegard's law to at least 6 at.% Sn. The solid solution α-Fe 0.92 Sn 0.08 was examined beyond the pressure of the α/ɛ-phase transition. The onset of the phase transition in α-Fe 0.92 Sn 0.08 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 A.