Ba₅(Al/Ga)₅(Sn/Pb): New Compounds at the Zintl Border.

Abstract

Structure D 2000Ba 5 (Al/Ga) 5 (Sn/Pb): New Compounds at the Zintl Border. -The new title phases are synthesized from stoichiometric mixtures of the elements at 900-1000 °C. The isotypic phases Ba5Al5Sn, Ba5Ga6Sn, Ba5Al5Pb and Ba5Ga5Pb crystallize with a new structure type in the hexagonal space group P6m2 with Z = 1 (single crystal XRD). Similar to the Zintl phases Ba2M (M: Sn, Pb; Co2Si structure type, orthorhombic, space group Pnma, Z = 4), the new ternary phases contain isolated M atoms coordinated by 11 Ba atoms. In addition, sheets of 3-and 4-bonded Al/Ga atoms similar to those in Ba3Al5 are present. The observed intergrowth is in accordance with the formula Ba3(Al,Ga)5·Ba2M. -(GUTTSCHE, K.; ROSIN, A.; WENDORFF, M.; ROEHR*, C.; Z. Naturforsch., B: Chem. Sci. 61 (2006) 7, 846-853; Inst. Anorg. Anal. Chem., Albert-Ludwigs-Univ., D-79104 Freiburg/Br., Germany; Ger., Abstr. Eng.) -Schramke 42-002

Structural and anisotropic elastic properties of Zintl M2Pb (M=Ca, Sr and Ba) compounds as a function of pressure

“…2, where V 0 , a 0 , and c 0 are their values at T = 0 K and P = 0 GPa, respectively. The calculated equilibrium V 0 and c/a of these Zintl compounds are in good agreement with experimental room-temperature data [2,7,24]. The results in Fig.…”

“…The optimized structural parameters for M 2 Pb (M = Ca, Sr, and Ba) compounds were listed in Table 1, along with the available experimental data [2,7,24]. The calculated lattice parameters of Ca 2 Pb, Sr 2 Pb and Ba 2 Pb compounds agree very well with the available experimental data within a difference of 1%.…”

Bonding Schemes for Polar Intermetallics through Molecular Orbital Models: Ca-Supported Pt–Pt Bonds in Ca10Pt7Si3

“…At the other extreme are the Hume-Rothery phases in which the low Δχ and χ values result in the vanishing of clear charge assignments or localized bonds [3]. The divide between the Zintl and Hume-Rothery has inspired the synthetic probing of their border for new phases with unique bonding and structures [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. A rich structural chemistry of polar intermetallic phases has resulted, which offers opportunities to chart how the close-shell electron configurations of the Zintl phases map to the delocalized bonding of the Hume-Rothery phases.…”