Superconductivity in low nitrogen concentration stabilized β-tungsten thin films

Abstract

We present a correlation between the crystalline structure and the superconducting critical temperature in beta-tungsten thin films stabilized by a low concentration of nitrogen impurities. The samples were deposited using reactive sputtering on silicon substrates at room temperature. Our findings indicate that when a minimal amount of nitrogen stabilizes the polycrystalline β-phase, the films exhibit a superconducting critical temperature of approximately 1.1 K. This value is considerably lower than 5 K, which is typically observed in amorphous and nitride thin films. Moreover, our results shed light on the differences in superconducting properties as disorder increases in nanocrystalline W thin films with potential applications in cryogenic electronic devices.