Investigation of Phase Relations for Binary Rare Earth MetalDisilicides.

Because of the tremendous economic importance for contact materials the Si-rich regions of transition metal - silicon systems are investigated in great detail. However, only few studies dedicated to the disilicide region of the rare earth metal - silicon systems exist. Thus the detailed phase relations of the phases occurring within the 60 to 70at% Si composition range having A1B 2 -type, GdSi2 -type, ThSi 2 -type, or not further described type crystal structure are only tentatively known. It is proposed to investigate these phase relations for the binary rare earth metal - silicon systems using XRD, metallography, DTA, and a less common method considered to be especially suitable for the clarification of stable and metastable phase equilibria: Smith thermal analysis. The results of this study might open the door to new technological applications of the rare earth metals as contact materials for silicon.