title: REAu2In4 (RE = La, Ce, Pr, Nd): polyindides from liquid indium.
abstract: The series of compounds REAu2In4 (RE = La, Ce, Pr, Nd) crystallize from excess In as rod-shaped single crystals. All members adopt the orthorhombic space group Pnma with a = 18.506(2) A, b = 4.6865(6) A, and c = 7.3414(9) A for LaAu2In4, a = 18.514(3) A, b = 4.6624(8) A, and c = 7.389(1) A for CeAu2In4, a = 18.420(4) A, b = 4.6202(9) A, and c = 7.376(2) A for the Pr analogue, and a = 18.406(2) A, b = 4.6114(5) A, and c = 7.4073(7) A for NdAu2In4. The REAu2In4 series can be regarded as polar intermetallic phases composed of a complex [Au2In4]3- polyanion network in which the rare-earth ions are embedded. The [Au2In4]3- network features In tetramer units, which defines the compounds as polyindides. Magnetic measurements found no magnetic ordering down to 2 K for any of the compounds. In addition, LaAu2In4 was found to be Pauli paramagnetic with a small susceptibility. Ab initio density functional methods were used to carry out electronic structure calculations to explore the bonding, the role of gold, and the contributions of different atoms to the density of states near the Fermi energy. We find that the density of states decreases slowly near Ef and reaches a minimum at about 0.5 eV above Ef.
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Salvador
authors.forename: Khang
authors.initials: K
authors.lastname: Hoang
authors.forename: S D
authors.initials: SD
authors.lastname: Mahanti
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis