Premium
Synthesis, Crystal Structure, and Ru/Ir Site Preference in the Complex Boride Series Ti 2 FeRu 5– x Ir x B 2 and Zr 2 Fe 1– δ Ru 5– x + δ Ir x B 2 ( x = 1–4, δ < 0.15)
Author(s) -
Hermus Martin,
Fokwa Boniface P. T.
Publication year - 2011
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.201100024
Subject(s) - tetragonal crystal system , crystallography , ruthenium , iridium , zirconium , materials science , crystal structure , boride , titanium , chemistry , metallurgy , biochemistry , catalysis
Polycrystalline samples and single crystals of the complex boride series Ti 2 FeRu 5– x Ir x B 2 and Zr 2 Fe 1– δ Ru 5– x + δ Ir x B 2 ( x = 1–4, δ < 0.15) were synthesized by arc melting the elements and characterized by powder and single‐crystal X‐ray diffraction as well as energy dispersive spectroscopy. All quinary phases could be synthesized in the titanium series, whereas only the first two ruthenium‐rich phases are stable and both are always present in nearly all synthetic targets of the zirconium series. These compounds crystallize in the tetragonal space group P 4/ mbm ( Z = 2) and they represent the first quinary substitutional variants of the Ti 3 Co 5 B 2 ‐type structure containing a mixture of 4d/5d transition metals. Their structures consist of layers of ruthenium and iridium atoms, building trigonal, tetragonal, and pentagonal prisms, in which the other elements are located. The trigonal prisms are filled with boron and the pentagonal prisms accommodate either titanium or zirconium. The tetragonal prisms are filled either with iron (in the Ti series) or with an iron‐rich Fe/Ru mixture (in the Zr series). Ruthenium and iridium share two sites in these structures leading to a strong size‐dependent site preference in both series.