Focused electron beam induced deposition (FEBID) is a nanofabrication technique, capable of creating a wide variety of size and shape selected metal-containing nanostructures using organometallic precursors. However, FEBID nanostructures often contain unacceptable amounts of contamination. This bottleneck in developing FEBID into a robust nanofabrication technology has provided the motivation to better understand the elementary reactions that occur during FEBID using a UHV surface science approach. An emerging aspect of FEBID involves the use of bimetallic organometallic complexes to create mixed metal nanostructures. In this presentation I will present findings on the electron stimulated reactions of two bimetallic complexes, CpFe(CO)2Mn(CO)5 and HFeCo3(CO)12 studied using in situ X-ray Photoelectron Spectroscopy and Mass Spectrometry. Several important mechanistic details previously observed for organometallics that contain a single metal atom (e.g. W(CO)6 and Pt(PF3)4) are retained in bimetallic complexes, such as (i) the two-step sequential process of electron-stimulated reactions involving ligand desorption followed by ligand decomposition, (ii) the existence of ligands that are preferentially desorbed during the first ligand desorption step (e.g. CO) and those that are retained and undergo decomposition (e.g. Cp). New findings include the observation that the fate of each metal atom appears to be determined from the nature of the surrounding ligands (i.e. electron stimulated reactions are localized). Moreover, the reason for the greater metal content often observed for bimetallic precursors appears to be a consequence of both the large fraction of volatile ligands ejected in the first step combined with the relatively inefficient electron-stimulated decomposition of the residual ligands.

Deposition of mixed metal nanostructures from bimetallic precursors using electrons: Insights from surface science

253rd National Meeting (2017)

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