Phase Equilibria of the Gd–Fe–B Ternary System at 873 and 1073 K

Abstract

The phase equilibria of the Gd–Fe–B ternary system at both 873 and 1073 K have been investigated by powder x-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The existence of ternary intermetallic compound Gd2Fe14B with Nd2Fe14B-type structure in space group P4 2 /mnm, GdFeB4 with YCrB4-type structure in space group Pbam, Gd5Fe2B6 with Pr5Co2B6-type structure in space group R $$ \bar{\textit{3}} $$ m, and Gd1.14Fe4B4 with Re1+x Fe4B4-type structure in space group Pccn was confirmed. The binary intermetallic compound Fe23Gd6 was found to be unstable, decomposing into two phases Fe17Gd2 and Fe3Gd, while the ternary intermetallic compound GdFe2B2 was not observed. The phase equilibria of the Gd–Fe–B ternary system at both 873 and 1073 K consist of 16 single-phase regions, 33 two-phase regions, and 18 three-phase regions.