title: Sc(2)MgGa(2) and Y(2)MgGa(2).
abstract: Scandium magnesium gallide, Sc(2)MgGa(2), and yttrium magnesium gallide, Y(2)MgGa(2), were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo(2)FeB(2)-type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc(2)MgGa(2 )was determined from single-crystal diffraction intensities and the isostructural Y(2)MgGa(2) was identified from powder diffraction data.
authors.affiliation: Department of Materials Chemistry, Box 538, SE-751 21 Uppsala, Sweden. martin.sahlberg@mkem.uu.se
authors.forename: Martin
authors.initials: M
authors.lastname: Sahlberg
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Andersson