Solid state phase equilibria in the Fe-Pt-Dy ternary system at 900°C

The solid state phase equilibria in the Fe-Pt-Dy ternary system at 900 degrees C (Dy <= 75 at.%) were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. It is found that the 900 degrees C isothermal section consists of 18 single-phase regions, 33 two-phase regions and 16 three-phase regions. At 900 degrees C, it is observed that the maximum solid solubility of Pt in Fe2Dy and alpha-(Fe, Dy) is 5 at.% Pt and 3 at.% Pt, respectively. The binary phase Fe5Dy was not observed. The existence of DyPt5, DYPt3, DYPt2, DY3Pt4, DyPt, DY5Pt4, Dy5Pt3, Dy2Pt and Dy3Pt compounds is confirmed and the maximum solubility of Fe in them is below I at.% Fe; the maximum solubility of Dy in alpha-(Fe, Pt), gamma-(Fe, Pt), FePt, FePt3 and (Pt, Fe) (the solid solution of Fe in Pt) is 3 at.% Dy, 2 at.% Dy, 2 at.% Dy, 1.5 at.% Dy and 1.5 at.% Dy, respectively. (c) 2006 Elsevier B.V. All rights reserved.