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The new structure type Gd 3 Ni 7 Al 14
Author(s) -
Pukas Svitlana,
Gladyshevskii Roman
Publication year - 2015
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229615018082
Subject(s) - prism , tetragonal crystal system , crystallography , polyhedron , type (biology) , hexagonal prism , triangular prism , crystal structure , hexagonal crystal system , materials science , trigonal crystal system , layer (electronics) , plane (geometry) , geometry , chemistry , optics , physics , geology , mathematics , nanotechnology , paleontology
The crystal structure of Gd 3 Ni 7 Al 14 (trigadolinium heptanickel tetradecaaluminide) belongs to a family of two‐layer structures and can be described as an assembly of interpenetrating centred straight prisms. For the Ni atoms, trigonal prisms (Al 4 Gd 2 and Al 6 ) are observed, the Al atoms are inside tetragonal (Ni 2 Al 2 Gd 4 , Ni 2 Al 4 Gd 2 , Al 4 Gd 4 , Ni 4 Al 4 and Al 8 ) and pentagonal (Ni 4 Al 6 and Al 10 ) prisms, while the Gd atoms are at the centres of pentagonal (Ni 4 Al 6 ) and hexagonal (Ni 4 Al 8 ) prisms. In each case, the true coordination polyhedron is a capped prism, also including atoms from the same layer. The structural features of Gd 3 Ni 7 Al 14 are similar to those of the intermetallides PrNi 2 Al 3 and ZrNiAl. In all these structures, Ni‐centred trigonal prisms form infinite columns via common triangular faces. The columns share prism edges and form a three‐dimensional framework with six‐membered rings in the (001) plane in the case of the PrNi 2 Al 3 and ZrNiAl types. In the case of Gd 3 Ni 7 Al 14 , six‐membered rings are also observed, but only two‐thirds of the rings are interconnected via prism edges.