Isothermal section of the Co–Er–Y ternary system at 500 °C

Abstract

The isothermal section of the phase diagram of the Co–Er–Y ternary system at 500 °C was investigated by X-ray powder diffraction technique, differential thermal analysis, scanning electron microscopy with energy dispersive analysis and optical microscopy. The 500 °C isothermal section consists of 14 single-phase regions, 19 two-phase regions, and 6 three-phase regions. Six pairs of corresponding compounds Er 2Co 17 and Y 2Co 17, Er 2Co 7 and Y 2Co 7, ErCo 3 and YCo 3, ErCo 2 and YCo 2, Er 4Co 3 and Y 4Co 3, Er 3Co and Y 3Co and metals Y and Er form a continuous series of solid solutions. The maximum solid solubility of Y in the compounds Er 12Co 7 is about 19 at.% Y.