A novel niobium nitride, U 2 S 3 -type Nb 2 N 3 , has been successfully synthesized by nitridation of δ-NbN above approximately 30 GPa in a laser-heated diamond anvil cell. Nb 2 N 3 crystallizes in the same orthorhombic structure (space group: Pnma) as η-Ta 2 N 3 . Nb 2 N 3 consists of regular-shaped polyhedra, and the bulk modulus has been determined to K 0 = 300(2) GPa. The low-temperature X-ray diffraction measurements have been successfully conducted for the tiny novel Nb 2 N 3 between 297.7(5) and 106.3(3) K under ambient pressure. Nb 2 N 3 shows no structural phase transition down to 106.3(3) K, and investigation of the linear thermal expansion coefficients yields α a = 3.36(9) × 10 −6 K −1 , α b = 5.39(10) × 10 −6 K −1 , α c = 6.77(15) × 10 −6 K −1 , respectively. Our study reveals that the incompressible novel nitride shows low thermal expansion behavior, which offers new insights for the development of functional nitrides and their crystal chemistry.U ltrahigh-pressure techniques allow one to synthesize novel transition-metal nitrides, pernitrides, and polynitrides, such as c-Zr 3 N 4 , 1 PtN 2 , 2 and FeN 4 . 3 These novel compounds are attracting attention from the viewpoints of superior mechanical and electronic properties and more. Among the early-transition-metal nitrides, in particular, niobium nitrides are considered to be extraordinary functional materials used as hard materials, 4 superconductors, 5,4 electrochemical capacitors, 6 and electrocatalysts. 7 Yet, most of the reported niobium nitrides, such as Nb

A novel high-pressure molybdenum nitride phase, Mo3N5, was synthesized at above 45 GPa via nitridation reaction for molybdenum with nitrogen under high pressure using a laser-heated diamond anvil cell. Mo3N5,...

We report the first synthesis of CuAl2-type VN2 and experimental investigation of the valence state for vanadium ions in VN2.