INFLUENCE OF Y (Gd) AND Ni (Fe) ON THE PRINCIPAL STRUCTURAI CHARACTERISTICS OF Al_(87)Y_(5 - x)Gd_xNi_(8 - y)Fe (x = 0-5; y = 0-4) AMORPHOUS METALLIC ALLOYS

摘要

The X-ray diffraction method is used to study the short-range ordering of Al_(87) Y_5 Ni_8, Al_(87) Gd_5 Ni_8, Al_(87) Y_4 Gd_1 Ni_8, Al_(87) Y_4 Gd_1 Ni_4 Fe_4, and Al_(87) Gd_5 Ni_4 Fe_4 amorphous alloys. The structural factors are obtained and the pair correlation functions are computed. The principal structural parameters are analyzed. It is shown that the investigated amorphous alloys are characterized by the topological short-range order based on the close-packed structure of aluminum and Al_3 Y(Gd)- and Al_3 Ni(Fe)-type chemical short-range ordering. It is discovered that the replacement of Y atoms with Gd atoms and Ni atoms with Fe atoms weakly affects the topology of the atomic distribution of the aluminum matrix and leads to changes in the character of chemical ordering. This affects the degree of short-range microhomogeneity of the short-range ordering and the dimensions of structural units.