The size-dependent morphology of Pd nanoclusters formed by gas condensation.

D Pearmain,S J Park,R E Palmer,A Abdela,Z Y Li

doi:10.1039/c5nr06473b

Abstract

Size-selected Pd nanoclusters in the size range from 887 to 10,000 atoms were synthesized in a magnetron sputtering, inert gas condensation cluster beam source equipped with a time of flight mass filter. Their morphologies were investigated using scanning transmission electron microscopy (STEM) and shown to be strongly size-dependent. The larger clusters exhibited elongated structures, which we attribute to the aggregation, through multiple collisions, of smaller clusters during the gas phase condensation process. This was confirmed from the atomically resolved STEM images of the Pd nanoclusters, which showed smaller primary clusters with their own crystalline structures.

Highlights

In order to fully exploit the potential applications of clusterbased nanomaterials, it is necessary to gain full control of the cluster size, shape and structure.[1,2,3,4,5,6,7] In terms of production, both wet chemical synthesis and physical methods have their advantages
Much progress has been made in gas phase approaches,[8] notably gas condensation magnetron sputtering[9,10] or laser vaporization.[11,12]
Gas phase synthesis allows for cluster mass selection prior to deposition on a support

Summary

Introduction

In order to fully exploit the potential applications of clusterbased nanomaterials, it is necessary to gain full control of the cluster size, shape and structure.[1,2,3,4,5,6,7] In terms of production, both wet chemical synthesis and physical methods have their advantages. Whilst the size (nuclearity) of gas-phase clusters can be selected with atomic precision in some cases,[13] the control of the shape and atomic structure of the deposited clusters remains a challenging task.

Results

Conclusion