In situ diffraction studies of the phase selection in undercooled Ti–Fe–Si–O melts

A time-resolved in situ determination of the phase formation sequence in undercooled Ti–Fe–Si–O melts was performed using the combination of electromagnetic levitation and energy-dispersive X-ray diffraction of synchrotron radiation. Ti–Fe–Si–O alloys are known to form a large variety of stable and metastable phases, including quasicrystals and approximant phases. Different solidification pathways are found as a function of undercooling, with the primary nucleation of the 1/1 crystal approximant phase from the liquid occurring at the largest undercoolings. The results on phase selection are discussed with respect to the influence of the short-range order in the undercooled liquid on the nucleation behavior of solid phases.