Electron microscopy studies of lutetium doped erbium silicide (Er0.9Lu0.1)5Si4

Examination of bulk microstructures of lutetium doped erbium silicide (Er0.9Lu0.1)5Si4 (space group: Pnma) using scanning and transmission electron microscopy (SEM, TEM) reveals the existence of thin plates of a hexagonal phase (space group: P63/mcm) where the stoichiometric ratio in moles between the rare earths and Si is 5 to 3, i. e the 5:3 phase. The orientation relationship between the matrix and the plates was determined as [010]m ≈ ∥[-1010]p. This observation adds credence to the assumption that all linear features noted in alloys of the rare-earth intermetallic family R5(SixGe1-x)4 are of the stoichiometric ratio 5:3 and possess a common orientation relationship with the parent 5:4 alloys.