Search

Abstract: We report on a structural distortion of kinetically stable B6‐based ferromagnetic Nb6FeIr6B8 that induces an unprecedented transformation of a ferromagnetic Fe chain into two ferrimagnetic Fe chains through superstructure formation. Density functional theory calculations showed that the ferromagnetic Fe–Fe intrachain interactions found in the undistorted structure become ferrimagnetic in the distorted superstructure, mainly because the two independent iron atoms building each chain interact antiferromagnetically and carry different magnetic moments. High‐temperature SQUID magnetometry confirmed ferrimagnetic ordering at 525 K with a high and negative Weiss constant of −972 K indicating the presence of strong antiferromagnetic interactions, as predicted. This finding paves the way for the development of low‐dimensional magnetic intermetallic systems based on Heisenberg ferrimagnetic chains, which have previously been studied only in molecular‐based compounds. [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. [ABSTRACT FROM AUTHOR]

Abstract: We report on a structural distortion of kinetically stable B6‐based ferromagnetic Nb6FeIr6B8 that induces an unprecedented transformation of a ferromagnetic Fe chain into two ferrimagnetic Fe chains through superstructure formation. Density functional theory calculations showed that the ferromagnetic Fe–Fe intrachain interactions found in the undistorted structure become ferrimagnetic in the distorted superstructure, mainly because the two independent iron atoms building each chain interact antiferromagnetically and carry different magnetic moments. High‐temperature SQUID magnetometry confirmed ferrimagnetic ordering at 525 K with a high and negative Weiss constant of −972 K indicating the presence of strong antiferromagnetic interactions, as predicted. This finding paves the way for the development of low‐dimensional magnetic intermetallic systems based on Heisenberg ferrimagnetic chains, which have previously been studied only in molecular‐based compounds. [ABSTRACT FROM AUTHOR]