Redetermination of the crystal structure of the Ag3Sn intermetallic compound

Abstract Ambiguity exists in the literature on the crystal structure of Ag 3 Sn: no agreement on neither the type of orthorhombic distortion nor the presence of ordering exists. Therefore, the exact crystal structure of Ag 3 Sn has been reinvestigated using high resolution X-ray powder dffraction. By applying Rietveld refinements, it could be shown that Ag 3 Sn is orthorhombic, with an ordered crystal structure of β-Cu 3 Ti-type (space group Pmmn ). The lattice parameters of a Sn-rich and an Ag-rich sample are a= 4.78233(1) Å, b= 5.99752(1) Å, c= 5.16393(1) Å and a= 4.78291(2) Å, b= 5.98854(2) Å, c= 5.15686(2) Å, respectively. The lattice parameters indicate κ-type orthorhombic distortion.