New quaternary complex borides, Ti9M2Ru18B8 (Cr, Mn, Co, Ni, Cu, Zn): synthesis, crystal structure and bonding analysis
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Boniface P. T. Fokwa
Abstract
Powder samples and single crystals of the Ti9M2Ru18B8 (Cr, Mn, Co, Ni, Cu, Zn) phases were synthesized from the elements and characterized by powder and single-crystal X-ray diffraction as well as energy-dispersive X-ray analysis. The new phases are all isotypic and crystallize in the tetragonal system as substitutional variants of the Zn11Rh18B8-type structure (space group P4/mbm, no. 127). M2 dumbbells are observed and interconnect to each other along the [001] direction to build “ladders”. The M–M dumbbell distances vary from 2.48 to 2.50 Å and the distances between two dumbbells (M2 · · · M2) are all close to 2.97 Å, whereas the chains are well separated from each other by distances of at least 11.20 Å. A strong variation of the unit cell volume with increasing valence electron count is observed in the series. According to the results of tight-binding electronic structure calculations, Ru–B and Ti–Ru contacts are responsible for the structural stability of these phases. The strength of the M–M and M–Ru interactions decreases with increasing valence electron count in the series. Non vanishing density of states at the Fermi level indicates metallic character for all phases.
© by Oldenbourg Wissenschaftsverlag, München, Germany
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- Preface
- At the edge of covalency: metallic nanotubes, low-dimensional metals and clusters
- Fast charge transport of titania nanotube arrays in dye-sensitized solar cells
- New quaternary complex borides, Ti9M2Ru18B8 (Cr, Mn, Co, Ni, Cu, Zn): synthesis, crystal structure and bonding analysis
- Polymorphism of isotypic series of homoleptic 1,2,3-triazolate MOFs [Ln(Tz*)3] containing the heavy lanthanides Gd–Lu: from open to dense frameworks of varying dimensionality
- From magnesium based intermetallics to metal hydrides: structures, properties and reaction pathways
- Crystal and magnetic structures of the complex perovskites LaCu3(Mn4–xFex)O12 with colossal magnetoresistance
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Articles in the same Issue
- Preface
- At the edge of covalency: metallic nanotubes, low-dimensional metals and clusters
- Fast charge transport of titania nanotube arrays in dye-sensitized solar cells
- New quaternary complex borides, Ti9M2Ru18B8 (Cr, Mn, Co, Ni, Cu, Zn): synthesis, crystal structure and bonding analysis
- Polymorphism of isotypic series of homoleptic 1,2,3-triazolate MOFs [Ln(Tz*)3] containing the heavy lanthanides Gd–Lu: from open to dense frameworks of varying dimensionality
- From magnesium based intermetallics to metal hydrides: structures, properties and reaction pathways
- Crystal and magnetic structures of the complex perovskites LaCu3(Mn4–xFex)O12 with colossal magnetoresistance
- An investigation of the polytypical structure of Sr0.2Ba0.8CoO3–δ by neutron powder diffraction
