The isothermal section of the Gd–Dy–Co ternary system at 800 K

Abstract

The isothermal section of the phase diagram of the Gd–Dy–Co ternary system at 800 K was investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA), optical microscopy and scanning electron microscopy (SEM) techniques. The result shows that this section consists of 9 single-phase regions and 9 two-phase regions, and 1 three-phase region. The compounds Gd 2Co 17 and Dy 2Co 17, Gd 2Co 7 and Dy 2Co 7, GdCo 3 and DyCo 3, GdCo 2 and DyCo 2, Gd 12Co 7 and Dy 12Co 7, Gd 3Co and Dy 3Co form a continuous series of solid solutions. In addition, the single phases α-Gd and α-Dy also form a continuous series of solid solution. The maximum solid solubility of Dy in Gd 4Co 3 is about 10.8 at.%. The binary compounds Dy 4Co 3, GdCo 5 and DyCo 5 were not observed at 800 K. No ternary compound was found.