The phase diagram of the Yb–Si system

The phase diagram of the Yb–Si system has been studied up to about 80 at.% Si by means of multitechnique investigations: differential thermal analysis (DTA), X-ray diffraction (XRD), optical microscopy (LOM), electron probe microanalysis (EMPA) and complemented with tensimetric measurements using the Knudsen effusion–mass spectrometry (KE–MS) and Knudsen effusion–weight loss (KE–WL) techniques. Besides the four already known intermediate phases: Yb5Si3 (Mn5Si3-type), YbSi (CrB-type), Yb3Si5 (Th3Pd5-type) and YbSi2−x (AlB2-type), two new compounds have been found and completely characterized: Yb5Si4 (Sm5Ge4-type) and Yb3Si4 (Ho3Si4-type). Two eutectics occur in this system: at less than 1 at.% Si (815 °C) and at about 82 at.% Si (1145 °C).