|
The isothermal section of the Er-Co-Nb ternary system at 773K has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion X-ray spectroscopy (EDS) techniques. The results confirmed the existence of seven binary compounds in the Er-Co binary system and two binary compounds in the Nb-Co binary system:Er2Co17, Er2Co7, ErCo3, ErCo2, Er4Co3, Er12Co7, Er3Co, NbCo2(A) and Nb6Co7(μ), respectively. Lattice parameters of these compounds were calculated except for Er4Co3. No ternary compound was found in this work. The maximum solid solubilities of Nb in the compounds Er2Co17, ErCo3, ErCo2, Er12Co7 and Er3Co are about 4.0,2.0,2.0, 4.0 and 4.0 at.% Nb, respectively. The composition range of Nb in the compounds NbCo2(X), Nb6Co7(μ) are about 27-33 at.% Nb and 46-54 at.% Nb. The maximum solid solubilities of Er in the compounds NbCo2, Nb6Co7 are about 2.0 at.% Er and 6.0 at.% Er.
|