Experimental re-determination and thermodynamic assessment of the erbium–zirconium system

The erbium–zirconium (Er–Zr) system has been completely reinvestigated experimentally. Particular attention was paid to the high purity of the raw materials, to the absence of oxygen contamination and to the control of the high vapor pressure of erbium. Several experimental techniques have been used to measure the solubility limits at different temperatures, the invariant points and the solidus and liquidus temperatures which were generally found to disagree with what was reported in the literature. As a result, the phase diagram presently obtained differs significantly from the accepted one and we propose a complete revision of the system. A thermodynamic assessment using the Calphad approach has been conducted. A set of parameters has been obtained allowing to describe well the experimental measurements.