A reinvestigation of the ScIn system and related (Tm,Lu)In compounds

Abstract

The phase diagram of the ScIn system has been revised in the range 30 to 100 at.% In using differential thermal analysis, metallographic analysis, X-ray diffraction and electron microscopy. Six intermediate phases have been found. Three of them have been confirmed: ScIn 3 (AuCu 3-type). Sc 2In (Ni 2In-type) and Sc 3In (Ni 3Sn-type), while Sc 3In 5 and Sc 5In 3 should be replaced by ScIn 2 (ZrGa 2-type) and ScIn respectively. The latter shows, however, a rather complex behaviour, assuming the CsCl- or AuCu-type structure, depending on composition. Tm 5In 4 and Lu 8In 4 (Ti 5Ga 4-type). LuIn (AuCu-type), Tm 3In 4 and Lu 3In 5 (Tm 3Ga 5-type) and LuIn 2 (ZrGa 2-type), previously unknown, have also been prepared and characterized for comparison.