Fabrication of β-Mo2C ultra-thin films by thermal annealing of molybdenum/carbon heterostructures

Abstract

Molybdenum carbide ultrathin thin films are obtained by thermal annealing of molybdenum/amorphous carbon heterostructures. The samples were grown at room temperature by magnetron sputtering on Si (1 0 0). As-grown samples display superconductivity, which could be related to the coexistence of crystalline and amorphous Mo. Interfacial β-Mo2C phase is observed after thermal annealing at 1033 K. Annealed samples display sharp superconducting transitions. A difference in the maximum critical temperature observed in trilayers and multilayers could be related to superconducting coupling between β-Mo2C layers.