Crystalline and Electronic Structures of the Al1+xV2Sn2–x(x= 0.19) Intermetallic Compound

A new ternary phase with a composition Al1+xV2Sn2–x(x= 0.19) has been found during investigation of the Al–V–Sn ternary system. Single-crystal X-ray diffraction measurements reveal that this ternary phase crystallizes with an orthorhombic structure with a= 5.5931(1) Å, b= 18.8017(5) Å, and c= 6.7005(2) Å (space group Cmce). This compound is thus isostructural to the GaV2Sn2structure type, showing a layered structure composed of vanadium cluster bands formed with pentagonal faces intercalated by Sn atom layers. High-resolution transmission electron microscopy measurements confirm the orthorhombic structure. Regarding lattice perfection, no dislocation could be identified within the probed Al1.19V2Sn1.81single-crystal lamella. Ab initio calculations reveal a reduction of the density of states at the Fermi level, which could be attributed to both a Hume–Rothery effect combined with strong spd hybridization.