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Nb2RuB2 and Ta2RuB2 phases were recently predicted by GGA-VASP structure optimization to crystallize in the Nb2OsB2-type structure. Although the Fe-based (Mo2FeB2 type) and Os-based (Nb2OsB2 type, superstructure variant of Mo2FeB2 type) analogues have been synthesized and characterized successfully, the Ru-based phases remained unknown. Crystal structure prediction of Nb2RuB2 and Ta2RuB2 phases, using an evolutionary algorithm, led to the AlMn2B2-type structure in contrast to the aforementioned optimization; however, phonon calculations showed that the Nb2OsB2-type phases are dynamically more stable than the AlMn2B2-type phases. A slightly modified synthetic strategy finally led to the successful preparation of the predicted phases. The extremely quick arc-melting procedure, under argon atmosphere, not only led to a quantitative amount of the phases but also to single crystals suitable for structure determination. Powder and single-crystal X-ray diffraction as well as EDX analysis of the metal ratio have confirmed the GGA-VASP structure optimization: Nb2RuB2 and Ta2RuB2 compounds indeed crystallize isotypically with Nb2OsB2 structure, a superstructure variant of Mo2FeB2 type, in which B-dumbbells and Peierls-distorted Ru-chains are found. Susceptibility measurements on a Ta2RuB2 single crystal reveal no superconducting transition down to 2 K, even though some features in the band structures of both phases, similar to those reported in superconducting NbRuB, hinted at possible superconductivity. [ABSTRACT FROM AUTHOR]

The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe1−xIr6+ xB8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe-Fe interactions found in the iron chains induce an unexpected strengthening of the B-B interactions in the B6 rings. Beside these strong B-B interactions, strong interlayer metal-boron bonds (Ir-B and Nb-B) ensure the overall structural stability of this phase, while the magnetic Fe-Fe interactions are mainly responsible for the observed ferromagnetic ordering below TC=350 K. [ABSTRACT FROM AUTHOR]

The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe1−xIr6+ xB8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe-Fe interactions found in the iron chains induce an unexpected strengthening of the B-B interactions in the B6 rings. Beside these strong B-B interactions, strong interlayer metal-boron bonds (Ir-B and Nb-B) ensure the overall structural stability of this phase, while the magnetic Fe-Fe interactions are mainly responsible for the observed ferromagnetic ordering below TC=350 K. [ABSTRACT FROM AUTHOR]

The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe1−xIr6+xB8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe – Fe interactions found in the iron chains induce an unexpected strengthening of the B – B interactions in the B6 rings. Beside these strong B – B interactions, strong interlayer metal – boron bonds (Ir – B and Nb – B) ensure the overall structural stability of this phase, while the magnetic Fe – Fe interactions are mainly responsible for the observed ferromagnetic ordering below TC=350 K. Eine gegenseitige Abhängigkeit von ferromagnetischen Eisenketten und gestapelten B6 ‐ Ringen (siehe Bild) wird in dem neuen ferromagnetischen Material Nb6Fe1−xIr6+xB8 (TC=350 K) durch Experimente und Dichtefunktionaltheorie gefunden. Starke magnetische Fe ‐ Fe ‐ Wechselwirkungen in den Eisenketten induzieren eine unerwartete Verstärkung der B ‐ B ‐ Wechselwirkungen in den B6 ‐ Ringen. [ABSTRACT FROM AUTHOR]

The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe1−xIr6+xB8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe–Fe interactions found in the iron chains induce an unexpected strengthening of the B–B interactions in the B6 rings. Beside these strong B–B interactions, strong interlayer metal–boron bonds (Ir–B and Nb–B) ensure the overall structural stability of this phase, while the magnetic Fe–Fe interactions are mainly responsible for the observed ferromagnetic ordering below TC=350 K. A mutual dependency between ferromagnetic iron chains and stacked B6 rings (see picture) is found in the new ferromagnetic material, Nb6Fe1−xIr6+xB8 (TC=350 K) by combining experiment and density functional theory (DFT). The strong magnetic Fe–Fe interactions found in the iron chains induce an unexpected strengthening of the B–B interactions in the B6 rings. [ABSTRACT FROM AUTHOR]

The synergistic combination of experiment and density functional theory has led to the discovery of the first ferromagnetic material, Nb6Fe(1-x)Ir(6+x)B8, containing in its crystal structure iron chains embedded in stacked B6 rings. The strong ferromagnetic Fe-Fe interactions found in the iron chains induce an unexpected strengthening of the B-B interactions in the B6 rings. Beside these strong B-B interactions, strong interlayer metal-boron bonds (Ir-B and Nb-B) ensure the overall structural stability of this phase, while the magnetic Fe-Fe interactions are mainly responsible for the observed ferromagnetic ordering below T(C)=350 K., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Members of the solid solution series of CeRu(1-x)Ni(x)Al can be obtained directly by arc melting of the elements. The presented compounds with 0.1 ≤ x ≤ 0.85 crystallize in the orthorhombic space group Pnma (No. 62) in the LaNiAl structure type, while for 0.9 ≤ x ≤ 1, the hexagonal ZrNiAl-type structure is found. The orthorhombic members exhibit an anomaly in the trend of the lattice parameters as well as an interesting behavior of the magnetic susceptibility, suggesting that the cerium cations exhibit no local moment. Besides the mixed-valent nature of the cerium cations, valence fluctuations along with a change in the cerium oxidation state depending on the nickel content have been found. The oxidation state has been determined from the magnetic data and additionally by XANES. Density functional theory calculations have identified the shortest Ce-Ru interaction as decisive for the stability of the orthorhombic solid solution.