Molybdenum was deposited from the vapour phase onto fused quartz and alumina at room temperature under simultaneous irradiation with energetic argon ions with different ion flux densities. It was observed that increasing ion irradiation intensity lead to a sight increase in grain size, to a reduction in oxygen incorporation from the residual gas, and to argon ion implantation. As a result, a strong reduction in resistivity was observed. On iron substrates, electrochemical polarization measurements showed a reduction in microporosity.