Ion distribution in iron oxide, zinc and manganese ferrite nanoparticles studied by XPS combined with argon gas cluster ion beam sputtering

In this work, the influence of X-ray irradiation and two types of surface sputtering methods is thoroughly studied. The first one, monoatomic sputtering, resulted in the reduction of iron oxide to the metallic iron in a short time of sputtering. The second studied technique is argon cluster sputtering, which uses lower energies per atom, hence the modification of the structure of the samples is greatly reduced. Based on the XPS characterization of Fe3O4 single crystal the fitting procedure for the Fe 2p spectra for nanoparticles is established. The preliminary results showed that X-rays combined with cluster sputtering resulted in alteration of the morphology and solidification of the surface of the samples. In the response to the morphology modification, the Spot-by-Spot Cluster Procedure is proposed. It allows to thoroughly characterize the layer-by-layer structure of the nanoparticles, without changing it. The Procedure was used to determine the structure of zinc, manganese and zinc-manganese ferrite nanoparticles. Finally, the results show, that depending on the used dopant, its incorporation and the state of iron are changed.

Automated summary

This work thoroughly investigates the influence of X-ray irradiation and two types of surface sputtering methods. Monoatomic sputtering reduces iron oxide to metallic iron in a short time, while argon cluster sputtering minimizes structural modifications. The Fe 2p spectra fitting procedure for nanoparticles is established based on XPS characterization of Fe3O4 single crystal. The combination of X-rays and cluster sputtering alters the morphology and solidifies the surface of samples. The Spot-by-Spot Cluster Procedure is proposed to characterize the layer-by-layer structure of nanoparticles without altering it. The structure of zinc, manganese, and zinc-manganese ferrite nanoparticles is determined using this procedure. Depending on the dopant, its incorporation and the state of iron are changed.