High Upper Critical Field and Type II Superconductivity in Epitaxial Cubic W2N Thin Films.

Transition Metal Nitrides (TMNs) are a versatile class of materials, combining chemical robustness, high hardness, and superconducting behaviour with critical temperatures between 2-10 K. While several binary TMNs have been explored, superconductivity in stoichiometric W2N has remained largely unexplored. Here, we report on superconducting thin films of stoichiometric W2N, demonstrating a distinctly high upper critical field (Hc2) of ∼ 8.5 T, uncommon among binary TMNs. This robust superconducting response under high magnetic fields highlights the technological relevance of W2N for integrated quantum and cryogenic electronic platforms. Overall, these results position stoichiometric W2N as a promising addition to the TMN superconducting landscape, opening new avenues for functional materials design based on chemically stable and mechanically resilient nitrides.