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Platinum Triangles in the Pt/Al Framework of the Intermetallic RE Pt 6 Al 3 ( RE = Ce–Nd, Sm, Gd, Tb) Series
Author(s) -
Eustermann Fabian,
Stegemann Frank,
Renner Konstantin,
Janka Oliver
Publication year - 2017
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201700090
Subject(s) - isostructural , crystallography , intermetallic , crystal structure , materials science , magnetic susceptibility , single crystal , magnetization , chemistry , metallurgy , physics , alloy , quantum mechanics , magnetic field
The compounds of the RE Pt 6 Al 3 series ( RE = Ce–Nd, Sm, Gd, Tb) were obtained by reaction of the elements via arc‐melting. They were characterized by powder and single‐crystal X‐ray diffraction (NdPt 6 Al 3 : wR = 0.0432, 759 F 2 values, 33 variables) as well as by magnetic susceptibility measurements. The isostructural compounds crystallize with a new structure type in the trigonal crystal system with space group R 3 c , twelve formula units in the unit cell, and lattice parameters of a = 752–755 and c = 3882–3945 pm. The crystal structure can be described by different slabs stacked along [001]. One layer features Pt 3 triangles, centering the cavities of a flat honeycomb RE layer that are arranged in a ···ABCA′B′C′··· sequence. The other layer consists of condensed hexagonal [Pt 6 Al 6 ] prisms, centered by Pt atoms, separating the before mentioned slabs. Magnetic measurements revealed that all rare‐earth atoms are in the trivalent oxidation state, however, due to the low lanthanoide content magnetic ordering phenomena were observed only at low temperatures [SmPt 6 Al 3 : T C = 5.0(1) K; GdPt 6 Al 3 : T C = 7.3(1) K; TbPt 6 Al 3 : T N = 3.6(1) K].