Morphology control of mass-selected platinum clusters fabricated by magnetron sputtering and their thermal stability study

Despite the decisive role of mass and morphology in cluster applications, achieving concurrent control over these parameters remains challenging. In this study, by incrementally increasing the argon flow rate in a magnetron sputtering system, mass-selected Pt2925 clusters with ±4.15% mass precision were successfully prepared with controllable morphological transition from quasi-spherical to multipodal. We attribute this Pt2925 morphological transition to a change in growth mode from atom addition to cluster–cluster collision, which is influenced by the nucleation process regulated by the argon flow rate. The signatures of the ion-beam current and mass spectrum provide a valuable guide for synthesizing mass-selected multipodal clusters in other elemental systems (Ru, Hf, and AuPd alloys). Moreover, the bipodal Pt2925 clusters retained their configuration both under prolonged high-dose electron-beam irradiation on amorphous carbon (∼200 s) and during in situ heating on amorphous SiN at 400 °C. These findings indicate that mass-selected bipodal Pt clusters exhibit good thermal stability and are promising for high-temperature applications.