High Upper Critical Field and Type II Superconductivity in Epitaxial Cubic W 2 N Thin Films

ABSTRACT 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 W 2 N has remained largely unexplored. Here, we report on superconducting thin films of stoichiometric W 2 N, demonstrating a distinctly high upper critical field ( H c2 ) of ∼ 8.5 T, uncommon among binary TMNs. This robust superconducting response under high magnetic fields highlights the technological relevance of W 2 N for integrated quantum and cryogenic electronic platforms. Overall, these results position stoichiometric W 2 N as a promising addition to the TMN superconducting landscape, opening new avenues for functional materials design based on chemically stable and mechanically resilient nitrides.