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-Fe33.3Ge66.7, Fe-Al65Ge35 и Ge-Al78Fe22 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 Al88Ge8Fe4, Al68Ge21Fe11, Al64Ge18Fe18, Al55Ge30Fe15 melts have been quenched by melt spinning technique. The fully amorphous state was obtained only for the Al55Ge30Fe15 ribbon, the one with composition Al68Ge21Fe11 is amorphous-crystalline and Al88Ge8Fe4 и Al64Ge18Fe18 ribbons are microcrystalline. A new hexagonal τ1 phase (a = 9.75(1) A, c = 8.80(1) A) in the ingot Al55Ge30Fe15 and Al41Ge39Fe20 alloys and a new tetragonal phase τ2 (a = 5.11(3) A, c = 4.60(2) A) in the ingot Al20Ge53Fe27 alloy have been found. The annealed at 623 K ribbons with composition Al88Ge8Fe4 and Al68Ge21Fe11 contain a new hexagonal phase τ3 (a = 6.709(5) A, c = 9.07(1) A), which is missing in the ingot.