Influence of oxygen on the glass formation of Mo–O binary alloys

Oxygen has usually been considered to be detrimental for the glass formation ability and rarely been taken as a main constituent of amorphous alloys. Here, the effect of oxygen on the glass formation of electrodeposited Mo–O binary alloys was systematically investigated by regulating the current density, and the existence of oxygen was found to promote and stabilize the glassy structure. Fully amorphous structure is obtained at the composition of 76 at.% Mo and 24 at.% O, which is close to the Mo–O binary eutectic point. With an increase in the current density from 0.4 to 2.5 A/cm², the oxygen content of the deposited films decreases from 24 to 14 at.%, leading to a transition in microstructure from fully amorphous to mixed amorphous/nanocrystalline. In addition, the crystallization behavior and mechanical properties of the as-deposited amorphous Mo₇₆O₂₄ films were studied. The present work not only shows a novel method for producing amorphous alloy with a high refractory metal and oxygen content, but also verifies that oxygen could act as a main constituent in the formation of amorphous alloys.