title: AuCd4: a Hume-Rothery Phase with VEC of 1.8 and icosahedral and trigonal-prismatic clusters as building blocks.
abstract: The η phase in the Au-Cd binary system has been synthesized, and the structure has been analyzed by single-crystal X-ray diffraction. The compound η-AuCd(4) crystallizes in the hexagonal space group P6(3)/m (No. 176). The unit cell contains ∼273 atoms. The compound AuCd(4) represents a √3a × √3a × c superstructure of the AgMg(4) type. The structure can be well described by icosahedral and trigonal-prismatic clusters. A phase transition to the high-temperature ε phase occurs exothermically at around 578 K. The compound is formed at a sharp valence electron concentration of 1.8 e/a. The compound can be understood within the framework of the Hume-Rothery stabilization mechanism.
authors.affiliation: CAS Chemical Centre, Lund University , Box 124, Getingevägen 60, Lund SE-22100, Sweden.
authors.forename: Partha P
authors.initials: PP
authors.lastname: Jana
authors.forename: Sven
authors.initials: S
authors.lastname: Lidin