The phase diagram of the Sr-Si system

The phase diagram of the Sr-Si system has been investigated across almost the whole composition range (0-75 at.% Si) using differential thermal analysis (DTA), metallographic analysis, X-ray diffraction and electron microscopy. Four intermediate phases exist: Sr2Si (PbCl2-type), Sr5Si3 (Cr5B3-type), SrSi (CrB-type) and the dimorphic SrSi2 compound. The low-temperature form alpha-SrSi2 is cubic, SrSi2-type, and the high-temperature form beta-SrSi2 is tetragonal with the alpha-ThSi2 structure-type. For this last phase a solid solubility range, from about 62.0 to 66.7 at.% Si, has also been found. Four eutectics occur in the system: at about 3 at.% Si and 745degreesC, 44 at.% Si and 1110degreesC, 61 at.% Si and 1055degreesC, 74 at.% Si and 1045degreesC. (C) 2003 Elsevier B.V. All rights reserved.