Crystal and electronic structures of the new quaternary RCr3Si2C (R=Y, Gd–Tm, Lu, U) compounds

Nine new quaternary intermetallic RCr3Si2C (R=Y, Gd–Tm, Lu, U) compounds have been synthesized and characterized by both powder and single-crystal X-ray diffraction. These compounds crystallize in the hexagonal system with space group P6/mmm and lattice parameters a∼9 Å and c∼4 Å. Single-crystal X-ray diffraction refinement evidences a new type-structure closely related to the YCo3Ga2-type. Electronic structure properties and crystal stability of real YCr3Si2C against hypothetical YCr3Si2 are discussed in view of the Korringa–Kohn–Rostoker calculations, accounting for models with different atomic occupancy on selected sites as well as emphasizing the role of carbon in stabilization of YCr3Si2C compound.

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► Crystal structure determination of the new intermetallic YCr3Si2C compound.
► New type-structure closely related to the YCo3Ga2-type.
► Theoretical study of the structural stability by electronic structure calculations.
► Crystal structure characterization of the entire RCr3Si2C series