Nature of critical current and coherent phenomena in granular MoNx thin films

Abstract

Investigations of the critical current versus temperature and applied magnetic field were carried out for granular MoNx films. All sampels display a two-stage superconducting transition and can be treated as a percolating network of SNS contacts with a Josephson coupling between grains. The temperature behavior of the critical current for the films studied is the same as the Ic(T) dependence for a SNS junction in the diffusive limit. The value of critical current in a magnetic field is governed by the pinning of Josephson vortices.