Nitridoborates of the Lanthanides: Synthesis, Structure Principles, and Properties of a New Class of Compounds

Abstract

Investigations of the nitridoborates of lanthanides (Ln) have progressed significantly during the last few years. New compounds have been synthesized and characterized and are presented here together with some of their properties. Currently two distinct methods serve for the preparation of nitridoborate compounds; either hexagonal boron nitride undergoes a fragmentation through the reaction with LnN, or dinitridoborate ions are converted into other nitridoborate ions. Lanthanide nitridoborates contain molecular anions such as [BN]n-, [BN2]3-, [B2N4]8-, [B3N6]9-, and [BN3]6- which may occur in combinations with other nitridoborates or with additional nitride ions. In crystal structures of lanthanide nitridoborates these anions are arranged in layers and are surrounded by metal atoms in a characteristic fashion. Terminal N atoms are capped by metal atoms forming a square-pyramid, and B atoms prefer a trigonal-prismatic environment of metal atoms. Nitridoborates form saltlike as well as metal-rich compounds and have the potential to show a lot of what are considered to be important solid-state properties, thus they have a good chance to establish their position within the group of relevant materials.

Rare-earth metal transition metal borocarbide and nitridoborate superconductors

“…Therefore, the suppression of the superconducting transition temperature in substituted samples is primarily caused by the reduction of N(E F ) concomitant to a decreasing coupling strength. This tendency is very similar to that observed in Co-substituted superconducting borocarbides YNi 2- [20] may originate from an unknown impurity phase [78].…”

“…A differentiation can be made between ternary nitridoborates with alkaline, alkaline-earth or rare-earth metals and quaternary ones which contain an additional transition metal. The former are typically salt-like compounds whereas the latter show metallic and in the case of La 3 Ni 2 [BN] 2 N also superconducting properties [17][18][19][20][21].…”

Capacity Enhancement and Discharge Mechanisms of Room‐Temperature Sodium–Sulfur Batteries

“…Afterwards, a substantial number of rare earth nitridoborates (boronitrides) was developed by solid state metathesis reactions, with ions such as [BN] n – , [BN 2 ] 3– , [BN 3 ] 6– , [B 2 N 4 ] 8– , and [B 3 N 6 ] 9– 8. The [BN] n – anion was characterized in ternary compounds [e.g.…”

Defect‐Related Luminescence in ­Nitridoborate Nitride, Mg3Ga(BN2)N2

“…During the last years, nitride‐based compounds have attracted considerable attention because of their potential applications in the field of luminescence, mainly as new materials for light‐emitting diodes 1–5. Nitridoborates with [BN] n – , [BN 2 ] 3– , [BN 3 ] 6– , [B 2 N 4 ] 8– , and [B 3 N 6 ] 9– ions are one of the most prominent group of nitride compounds 6. The di‐nitridoborate ion was first identified in Li 3 (BN 2 ) and AE 3 (BN 2 ) 2 by Goubeau and Anselment,7 but the crystal structures of these compounds were reported many years later 8,9.…”

“…A great number of nitridoborate compounds have been synthesized by conducting solid‐state metathesis (SSM) reactions between rare earth halides and lithium dinitridoborate 17. This type of reaction does not require high temperatures because it uses the intrinsic energy of the reaction partners involved.…”