Metastable superconductivity of Mo/MoO 3 − x interface

Highlights: • Mo/MoO${}_{3-x}$ interface was formed by surface oxidation of Mo. • Magnetic susceptibility and electrical resistance of the interface was studied. • Superconductivity at 38–55 K of the Mo/MoO${}_{3-x}$ interfaces was observed. • The superconducting interface is instable under normal conditions. -- Abstract: Superconducting at 38 ≤ T ≤ 55 K metastable Mo/MoO${}_{3-x},$ 0 ≤ x ≤ 0.25, interfaces have been prepared by means of a redox reaction of Mo-metal with powdered α-MoO₃. The ac magnetic susceptibility and electrical resistance measurements suggest that the Mo/MoO${}_{3-x}$ interfacial layer is consisting of weakly connected superconducting regions.