Studies on the rules for amorphous phase formation by ion-mixing in metallic systems

Ion mixing (IM) has been of considerable interest over the last several years.¹ It has emerged as a convenient method to produce various amorphous and metastable crystalline phases.² Several attempts have been made to predict the formation of amorphous phases by this technique. Liu and coworkers have formulated a rule which states that an amorphous binary alloy will be formed by IM of the multilayered sample when the two constituent metals are of different structures.³ it has also been suggested that IM is likely to produce a crystalline phase at a composition which corresponds to a compound of simple lattice structure.⁴ Recently, the application of thermodynamic considerations to IM processes have proven fruitful.^5,6 The present authors have provided some general criteria regarding amorphous and crystalline phases formation by IM of metal-metal systems based on considerations of thermodynamic free energy diagrams and the restricted growth kinetics of competing phases. In this paper we shall examine these ideas by studying the IM of metal-metal systems of Ru-Zr and Ru-Ti.