Structure of the Al–Ge–Fe alloys in the liquid and solid state

Abstract X-ray diffraction study of liquid and solid Al–Ge–Fe alloys along the sections Al-Fe 33.3 Ge 66.7 , Fe-Al 65 Ge 35 и Ge-Al 78 Fe 22 has been discussed. It has been shown that addition of third component to the corresponding binary melt leads to the atomic clusters with structure similar to liquid germanium due to energy inequality of interactions in Al–Fe and Fe–Ge pairs and competition between Al and Ge atoms in formation of local structure around Fe atoms in the ternary melts. The Al 88 Ge 8 Fe 4 , Al 68 Ge 21 Fe 11 , Al 64 Ge 18 Fe 18 , Al 55 Ge 30 Fe 15 melts have been quenched by melt spinning technique. The fully amorphous state was obtained only for the Al 55 Ge 30 Fe 15 ribbon, the one with composition Al 68 Ge 21 Fe 11 is amorphous-crystalline and Al 88 Ge 8 Fe 4 и Al 64 Ge 18 Fe 18 ribbons are microcrystalline. A new hexagonal τ 1 phase ( a  = 9.75(1) A, c  = 8.80(1) A) in the ingot Al 55 Ge 30 Fe 15 and Al 41 Ge 39 Fe 20 alloys and a new tetragonal phase τ 2 ( a  = 5.11(3) A, c  = 4.60(2) A) in the ingot Al 20 Ge 53 Fe 27 alloy have been found. The annealed at 623 K ribbons with composition Al 88 Ge 8 Fe 4 and Al 68 Ge 21 Fe 11 contain a new hexagonal phase τ 3 ( a  = 6.709(5) A, c  = 9.07(1) A), which is missing in the ingot.