Exploring nucleation of ALD-fabricated Pt nanoparticles through X-ray total scattering

Atomic layer deposition (ALD) holds significant potential for precise atomic control over the morphology and dimensions of metal nanoparticles (NPs) during their nucleation phase.[1] Exercising control over the nucleation process is crucial for the deposition of supported metal NPs with tunable metal loading, particularly for applications such as NP catalysts.[2] Herein, we present high-quality grazing-incidence X-ray total scattering/pair distribution function (GIPDF) patterns of the initial stages of platinum nucleation (MeCpPtMe3-O2 at 300 °C), which have been successfully obtained at ESRF, ID15A beamline, and modeled. The background-subtracted PDF profiles were analyzed using the spheroid attenuated crystal model alongside a more complex, atomistic model (refer to Figure 1 for a representative fitted PDF profile), providing insights into various structural parameters, including size, cluster motifs, shape, and lattice constant. The presented methodology offers a framework to leverage and extract structural information during the initial growth stages of ALD, thus paving the way for foundational insights into the nucleation chemistry that underpins metal ALD processes. [1] K. T. Dinh, et al. Chem. Mater, 2023, 35, 6, 2248–2280. [2] J. Lu, et al. Acc. Chem. Res, 2013, 46, 8, 1806–1815.