Synthesis and Structure of Two New Ternary Nitrides:  FeWN₂ and MnMoN₂

Abstract

New layered ternary transition metal nitrides, FeWN2 and MnMoN2, were synthesized in single-step reactions by the ammonolysis of ternary transition metal oxides. Solid-state precursors FeWO4 and MnMoO4 were treated with ammonia at 625 and 800 °C to yield the ternary nitrides FeWN2 (P63/mmc; a = 2.87630(5) Å, c = 10.9320(4) Å) and MnMoN2 (P63/mmc; a = 2.92262(8) Å, b = 10.8564(4) Å), respectively. Structures are proposed on the basis of Rietveld analysis of powder X-ray diffraction data. These compounds are members of a family of layered hexagonal ternary nitrides, consisting of alternating layers of MN6 (M = Fe, Mn) octahedra and M‘N6 (M‘ = W, Mo) trigonal prisms. The conductivity data for both compounds indicate metallic-like behavior.

Octahedral and trigonal-prismatic coordination preferences in Nb-, Mo-, Ta-, and W-based ABX2 layered oxides, oxynitrides, and nitrides

“…It is possible to assess this relationship between electron counts and structures in compounds with 3d transition metals in the A sites, such as FeWN2 [50][51][52][53], MnWN2 [54], and MnMoN2 [50]. These materials have layered structures consisting of octahedral layers with 3d transition metals and trigonalprismatic layers with 4d or 5d metals.…”

Synthesis and Characterization of the New Ternary Nitride (Fe0.8W0.2)WN2

“…Of particular note are the recent syntheses of ternary nitrides containing two transition metals starting from the appropriate ternary oxide, demonstrating that complete conversion to a nitride product is possible (15,18). Also, the ammonolysis of lithium molybdate and tungstate precursors yields ternary nitride materials with structures remarkably similar to those found in lithium intercalated molybdenum and tungsten dichalcogenides.…”

Alkaline‐earth Metal Nitrides of the Main‐Group Elements: Crystal Structures and Properties of Inverse Perovskites

“…Similar behavior is known from ternary inter-transition metal nitrides as, e.g., FeWN 2 and MnMoN 2 . [71][72][73] The temperature dependencies of the magnetic susceptibilities of the four known Sr and Ba phases can be interpreted as the sums of diamagnetic core contributions, weakly temperature dependent Pauli paramagnetic terms and minor Curie impurities. The resulting Pauli paramagnetic contribution indicates quite similar electronic densities of states at the Fermi level for all four phases (A 3 N)E with A = Sr, Ba; E = Sb, Bi of about 7.5 states per eV, in qualitative agreement with electronic band structure calculations (see below).…”