In situ TEM observation of spontaneous alloying in nanometer-sized particles

Abstract

The alloying behaviour in nanometer (nm)-sized particles was studied by transmission electron microscopy (TEM). When solute atoms are vapour-deposited onto nm-sized particles at room temperature, rapid dissolution of solute atoms into particles occur, and solid solution or compound particles are successfully formed. Such spontaneous alloying occurs even between nm-sized particles of different elements. Our results can be summarized as: (i) spontaneous alloying takes place via a solid-state process, (ii) spontaneous alloying becomes more difficult with increasing particle size, (iii) spontaneous alloying is not an artifact originating from the temperature rise in particles which might be induced by heat of condensation and (iv) remarkable enhancement of solubility is observed in nm-sized compound particles.