tungsteniinit

Tungsteniinit (tungsten nitrides) are a family of binary and non-stoichiometric compounds composed of tungsten and nitrogen. The general formula WxNy includes well-known members such as tungsten nitride (WN) and other stoichiometries such as WN2. These materials are studied for their extreme hardness, high thermal stability, and chemical inertness, which make them candidates for protective coatings and diffusion barriers. The exact crystal structure varies with composition and synthesis conditions; reported structures include hexagonal and cubic polymorphs, as well as non-stoichiometric phases.

They are typically prepared by high-temperature solid-state synthesis or by thin-film deposition techniques such as reactive magnetron sputtering, chemical vapor deposition, or atomic layer deposition, often from a tungsten source in nitrogen-containing atmospheres. Non-stoichiometric nitrides can be formed by adjusting nitrogen activity, temperature, and pressure. Properties depend on composition and microstructure; many tungsten nitrides exhibit high hardness and wear resistance, good oxidation resistance, and electrical conductivity, though some phases may be semiconducting or insulating.

Applications include protective coatings for cutting tools and wear parts, diffusion barriers in microelectronics, and potential catalytic or electrocatalytic uses. Stability under operating conditions varies; some nitrides may oxidize or transform at elevated temperatures in air. Tungsteniinit are the subject of ongoing research to tailor properties via alloying, layering, and size effects.