Fractional Brownian motion of an Al nanosphere in liquid Al-Si alloy under electron-beam irradiation

Fractional forces and Brownian motion are expected to govern the behavior of nanoscale metallic solids in liquids, but such systems have not been studied. We investigated the motion of a crystalline Al nanosphere inside a partially molten Al-Si alloy particle, using an electron beam to both stimulate and observe the motion of the nanosphere. The irregular motion observed was quantified as antipersistant fractional Brownian motion. Analysis of possible phenomena contributing to the motion demonstrates that the incident electrons provide the fractional force that moves the Al nanosphere and that gravity and the oxide shell on the partially molten particle cause the antipersistant behavior