Mika T. Structure, electrical, magnetic and electrochemical properties of amorphous and crystallized alloys Al87Y5Ni8, doped by Gd (Dy) and/or Fe

Investigation of structure, electrical resistivity, magnetic and electrochemical properties of amorphous metallic alloys based on composition Al87Y5Ni8, doped with Gd (Dy) and/or Fe and products of their crystallization has been done. It was shown that replacement of Y by Gd or Dy atoms decreases thermal stability of alloys, replacement of Ni by Fe atoms shifts primary crystallization to higher temperatures. All investigated AMAs (except for Al87Dy5Fe8) crystallize in three stages. The first two stages of crystallization correspond to the formation of nanocrystals of Al(R) solid solution, the third stage – correspond to formation of IMC R3Ni5Al19 (R = Y, Gd, Dy). Crystallization of alloys containing of Fe is concerned with the formation of IMC RM4Al8 (R = Y, Gd, Dy; M = Fe, Ni). Crystallization of Al87Dy5Fe8 AMA occurs in 5 stages with the formation of unidentified IMC. The phase equilibria of the R-Ni-Al (R = Y, Gd) ternary systems in the region 65-100 at. % Al at 773 K were reinvestigated and predicting of crystallization products on the last stage of crystallization of other amorphous metallic alloys with high content of Al has been done. It was shown, that electrical resistance of all investigated AMAs decreases with partial replacement of Y by Gd or Dy, and increases with substitution of Ni by Fe. Magnetic properties of AMAs indicate the formation of superparamagnetic clusters of Ni. It was found that the nanocrystallization improves corrosion resistance of all investigated alloys in 0.1 М NaCl aqueous solution.