Croatica Chemica Acta, Vol. 68 No. 4, 1995.
Izvorni znanstveni članak
BaCu5Al8: A Structure Containing Interconnected [Al8Cu4]2- Icosahedra
Karen J. Nordell
; Department of Chemistry, Iowa State University, Ames, Iowa, 50011 USA
Gordon J. Miller
; Department of Chemistry, Iowa State University, Ames, Iowa, 50011 USA
Sažetak
BaCu5Al8 was synthesized from stoichiometric amounts of the elements by heating in a tube furnace or melting in an arc welder. BaCu5Al8 forms a variation of the NaZn13 structure in which large Ba2+ cations are surrounded by a three-dimensional network of interconnected Cu-centered, [Al8Cu4]2- icosahedra. The compound was characterized by both powder and single crystal X-ray diffraction. BaCu5Al8 crystallizes in the space group Fm5c (no.226); a = 12.2049(38) Å; Z = 8; R = 0.018; Goof = 1.16. EUCU5A18 was characterized by powder X-ray diffraction, and lattice parameters were refined from the measured 2-theta values; a = 11.9715(19) A. Magnetic susceptibility for both BaCusAlg and EuCu5Al8, and resistivity measurements on EuCu5Al8 are reported. Extended Hückel calculations on stoichiometries ranging from BaCu13 to BaCuAl12, demonstrate the tuning of the system’s stoichiometry to balance the Fermi energy and overlap populations.
Ključne riječi
Hrčak ID:
136695
URI
Datum izdavanja:
1.11.1995.
Posjeta: 711 *