Zn(13)(Cr(x)Al(1-x))(27) (x=0.34-0.37): a new intermetallic phase containing icosahedra as building units
|Title||Zn(13)(Cr(x)Al(1-x))(27) (x=0.34-0.37): a new intermetallic phase containing icosahedra as building units|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Thimmaiah S, Khan M, Miller GJ|
|Journal Title||Zeitschrift Fur Kristallographie|
The title compounds Zn(13)(Cr(x)Al(1) (-) (x))(27) (x = 0.34-0.37) were obtained by melting the pure elements at 923 K, and followed by a heat treatment at 723 K in a tantalum container. According to single crystal structural analysis, the title compounds crystallize in the rhombohedral system, adopting a new structure type (R (3) over barm, a = 7.5971(8), c = 36.816(6), for crystal I). Single crystal X-ray structural analysis reveals a statistical mixing of Cr/Al in their crystallographic positions. Single crystal and powder X-ray diffraction as well as energy dispersive X-ray analyses suggested the title phase to have a narrow homogeneity range. The substructure of Zn(13)(Cr(x)Al(1) (-) (x))(27) shows close resemblance with the Mn(3)Al(10) structure type. A bonding analysis, through crystal orbital Hamiltonian populations (COHPs), of "Cr(9)Al(18)Zn(13)" as a representative composition indicated that both homo- and heteronuclear interactions are important for the stability of this new phase.